Section 600.100  Definitions

 

Definitions of terms in the International Energy Conservation Code, incorporated by reference in Subpart C of this Part, apply, as do the following definitions:

 

"2024 International Energy Conservation Code Final Draft" means the Public Comments Draft 2 version of the 2024 IECC with approved proposals from the Committee Action Report.

 

"Act" means the Capital Development Board Act [20 ILCS 3105].

 

"Authority Having Jurisdiction" or "AHJ" means the organization, office or individual responsible for approving equipment, materials, an installation or procedure.

 

"CDB" or "Board" means the Illinois Capital Development Board.

 

"Commercial Facility" means any building except a building that is a residential building as defined in the EEB Act.  [20 ILCS 3125/10]

 

"Council" means the Illinois Energy Conservation Advisory Council appointed under Section 600.120 and whose purpose it is to recommend modifications to the Illinois Energy Conservation Code.

 

"EEB Act" means the Energy Efficient Building Act [20 ILCS 3125].

 

"IECC" means the International Energy Conservation Code.

 

"Illinois Energy Conservation Code" means:

 

With respect to the privately funded commercial facilities covered by Subpart C Section 600.300:

 

This Part, all additional requirements incorporated within Subpart C (including the 2021 International Energy Conservation Code that encompasses ASHRAE 90.1, including all published errata but excluding published supplements, and any statutorily authorized adaptations to the incorporated standards adopted by CDB; and

 

With respect to the residential buildings covered by Subpart D Section 600.400:

 

This Part, all additional requirements incorporated within Subpart D (including the 2021 International Energy Conservation Code, including all published errata but excluding published supplements) and any statutorily authorized adaptations to the incorporated standards adopted by CDB.

 

"Illinois Commercial Stretch Energy Code" or "Commercial Stretch Code" means:

 

With respect to the State facilities covered by Subpart B and privately funded commercial facilities covered by Subpart C Section 600.305:

 

This Part, all additional requirements incorporated within Subparts B and C (including the 2024 International Energy Conservation Code Final Draft Commercial Provisions that encompasses ASHRAE 90.1, including all published errata but excluding published supplements) and any statutorily authorized adaptations to the incorporated standards adopted by CDB;

 

"Illinois Residential Stretch Energy Code" or "Residential Stretch Code" means:

 

With respect to the residential buildings covered by Subpart D Section 600.405:

 

This Part, all additional requirements incorporated with Subpart D (including the 2021 International Energy Conservation Code Residential Provisions, including all published errata but excluding published supplements) and any statutorily authorized adaptations to the incorporated standards adopted by CDB.

 

"Municipality" means any city, village, or incorporated town.  [20 ILCS 3125/10]

 

"Residential Building" means a detached one-family or 2-family dwelling or any building that is 3 stories or less in height above grade that contains multiple dwelling units, in which the occupants reside on a primarily permanent basis, such as a townhouse, a row house, an apartment house, a convent, a monastery, a rectory, a fraternity or sorority house, a dormitory, and a rooming house; provided, however, that when applied to a building located within the boundaries of a municipality having a population of 1,000,000 or more, the term "residential building" means a building containing one or more dwelling units, not exceeding 4 stories above grade, where occupants are primarily permanent.  [20 ILCS 3125/10]

 

"State Funded Building" means and includes buildings under the jurisdiction of each officer, department, board, commission, institution and body politic and corporate of the State, including the Illinois Building Authority, and any other person expending or encumbering State or federal funds by virtue of an appropriation or other authorization by the General Assembly or federal authorization or grant.  This includes State funded housing, hospitals, penitentiaries, laboratories, educational facilities, administrative facilities, recreational facilities, environmental equipment and parking facilities [20 ILCS 3105/4.01].

 

(Source:  Amended at 48 Ill. Reg. 14276, effective January 1, 2025)

 

Section 600.110  Adoption and Modification of the Illinois Energy Codes

 

a)         The purpose of the Illinois Energy Conservation Code is to implement Section 15 of the Energy Efficient Building Act [20 ILCS 3125] that requires CDB to officially adopt, as a minimum requirement for commercial structures and as a minimum and maximum requirement for residential buildings, the 2021 International Energy Conservation Code, including all published errata but excluding any published supplements, to apply that Illinois Energy Conservation Code to all commercial and residential structures in Illinois, and to assist local code officials with enforcing the requirements of the Illinois Energy Conservation Code. The 2021 Illinois Energy Conservation Code will become effective on January 1, 2024.

 

b)         The purpose of the Illinois Stretch Energy Code as described in Subparts B, C, and D (State facilities, privately-funded commercial facilities and residential buildings) is to implement Section 55 of the Energy Efficient Building Act [20 ILCS 3125] that requires CDB to officially adopt, as a minimum requirement for State facilities, commercial structures and residential buildings in municipalities that have adopted the Illinois Stretch Energy Code, an energy code that meets the site energy indexes as outlined in Section 55 of the Energy Efficient Building Act.

 

c)         The Illinois Energy Conservation Code as described in Subpart C (privately-funded commercial facilities) is effective April 8, 2007. The Illinois Energy Conservation Code as described in Subpart D (residential buildings) is effective January 29, 2010.  The Illinois Stretch Energy Code as described in Subparts B, C and D (State facilities, privately-funded commercial facilities and residential buildings) is effective January 1, 2025.

 

d)         Application of the Codes

 

1)         State Facilities.  The Illinois Commercial Stretch Energy Code as described in Subpart B of this Part applies to all projects to which an energy conservation code is applicable that are authorized or funded in any part by the Board after July 1, 2024.  [20 ILCS 3125/55]

 

2)         Privately Funded Commercial Facilities and Residential Buildings.  The Illinois Energy Conservation Code or the Illinois Stretch Energy Code if adopted by the local municipality as described in Subparts C and D of this Part applies to any new building or structure in this State for which a building permit application is received by a municipality or county.  [20 ILCS 3125/20] 

 

A)        Additions, alterations, renovations, or repairs to an existing building, building system or portion thereof shall conform to the provisions of the Code as they relate to new construction without requiring the unaltered portion of the existing building or building system to comply with the Code.  [20 ILCS 3125/20(c)]

 

B)        All exceptions listed in the Code related to additions, alterations, renovations, or repairs to an existing building are acceptable provided the energy use of the building is not increased.

 

e)         This Code, together with the standards incorporated by reference in this Part, has the force of a building code and is administrative law applicable in the State of Illinois.

 

(Source:  Amended at 48 Ill. Reg. 14276, effective January 1, 2025)

 

Section 600.120  Illinois Energy Conservation Advisory Council

 

a)         The Executive Director of the Capital Development Board shall appoint an Advisory Council.  The Council shall be composed of the Executive Director or his or her authorized representative, who shall serve as Chairman ex-officio, and 16 additional members appointed by the Executive Director.  The appointed members shall consist of 1 person representing the Illinois Environmental Protection Agency; 2 persons representing the residential construction contracting industry; 2 licensed architects; 1 licensed mechanical engineer; 1 licensed electrical engineer; 2 persons representing local code officials; and 2 persons representing the construction contracting industry; 1 representative from a group that represents environmental justice; 1 representative of a nonprofit or professional association advocating for the environment; 1 energy-efficiency advocate with technical expertise in single-family residential buildings; 1 energy-efficiency advocate with technical expertise in commercial buildings; and 1 energy-efficiency advocate with technical expertise in multifamily buildings, such as an affordable housing developer.  Members of the Council shall be appointed for 4 year terms.  The members appointed by the Executive Director shall serve for the term of their appointments or until their successors are appointed and may be reappointed upon expiration of the term.  Any member appointed to fill a vacancy occurring prior to the expiration of the term for which the member's predecessor was appointed shall be appointed for a full term.

 

b)         Nine members of the Council shall constitute a quorum. The Chairman shall only vote to break a tie or when necessary to establish a quorum.

 

c)         The purpose of the Council shall be to recommend modifications to the Illinois Energy Conservation Code and the Illinois Stretch Energy Code.

 

d)         Members of the Council shall serve without compensation but shall be reimbursed for reasonable travel expenses necessarily incurred in the performance of their duties.

 

(Source:  Amended at 48 Ill. Reg. 14276, effective January 1, 2025)

 

Section 600.125  Illinois Energy Conservation Advisory Council Meetings

 

a)         Public comment will be allowed at the end of each meeting for a period not to exceed 30 minutes or at other times as designated by the Chair.  Each person making a public comment will be given up to three minutes of uninterrupted time to speak. 

 

b)         Public comment will be allowed prior to voting on any motion.  Each person making a public comment will be given up to three minutes of uninterrupted time to speak.

 

c)         The Chair may impose other time restrictions as may be necessary to accommodate all persons wishing to make comment.

 

d)         Public comment is not permitted except at designated times unless requested by the Chair.

 

e)         Public comment that is deemed by the Chair to be disruptive to the meeting and prevents the Council from accomplishing its business in an efficient manner, will not be allowed.

 

f)         The council is not required to answer or respond to any public comment.

 

(Source:  Added at 48 Ill. Reg. 14276, effective January 1, 2025)

 

Section 600.130  Revisions to the Code

 

This Code may be revised by the Capital Development Board on its own volition or pursuant to recommendations of the Illinois Energy Conservation Advisory Council and in accordance with the Illinois Administrative Procedure Act [5 ILCS 100].

 

Section 600.200  Illinois Commercial Stretch Energy Code

 

a)         The 2024 IECC Final Draft, including published errata but excluding published supplements, available from the Capital Development Board, 401 S. Spring St., 3^rd Floor, Springfield, IL  62706 (cdb.energycodes@illinois.gov) through copyright agreement with International Code Council at 200 Massachusetts Ave, NW Suite 250, Washington DC  20001, phone: 1-888-ICC-SAFE (422-7233), www.iccsafe.org, is hereby incorporated into the Illinois Commercial Stretch Energy Code, as described in this Subpart as applicable to State funded facilities, with the modifications outlined in subsection (c).

 

b)         All incorporations by reference in this Section are of the cited standards as they existed on the date specified.  These incorporations include no later editions or amendments.

 

c)         Modifications to IECC

Under Section 55 of the EEB Act, when applying the Illinois Commercial Stretch Energy Code to State funded facilities, CDB may modify the incorporated standards to meet objectives outlined in the EEB Act.  Modifications, additions or omissions to the IECC Final Draft are specified in Appendix B and are rules of the CDB and are not requirements of the IECC.

 

(Source:  Amended at 48 Ill. Reg. 14276, effective January 1, 2025)

 

Section 600.210  Exemptions

 

a)         The following buildings are exempt from the Code:

 

1)         Buildings otherwise exempt from the provisions of a locally adopted building code and buildings that do not contain a conditioned space;

 

2)         Buildings that do not use either electricity or fossil fuel for comfort conditionings;

 

3)         Historic buildings listed on the National Register of Historic Places or the Illinois Register of Historic Places, and those buildings that are designated by authorized personnel as historically significant;

 

4)         Other buildings specified as exempt by the IECC.

 

b)         For purposes of determining whether an exemption authorized under subsection (a)(2) applies, a building will be presumed to be heated by electricity, even in the absence of equipment used for electric comfort heating, whenever the building is provided with electrical service in excess of 100 amps, unless the code enforcement official determines that this electrical service is necessary for purposes other than providing electric comfort heating. [20 ILCS 3125/20]

 

(Source:  Amended at 43 Ill. Reg. 8707, effective August 5, 2019)

 

Section 600.220  Compliance

 

Compliance with the Illinois Commercial Stretch Energy Code for State facilities as described by this Subpart B shall be demonstrated by submission of one of the following:

 

a)         Buildings certified in compliance with Passive House Institute (PHI) or Passive House Institute U.S. (PHIUS) programs;

 

b)         Compliance Certificates generated by the U.S. Department of Energy's COMcheck code compliance tool; or

 

c)         The seal of the architect/engineer as required by Section 14 of the Illinois Architecture Practice Act [225 ILCS 305], Section 12 of the Structural Engineering Licensing Act [225 ILCS 340] and Section 14 of the Illinois Professional Engineering Practice Act [225 ILCS 325].

 

(Source:  Amended at 48 Ill. Reg. 14276, effective January 1, 2025)

 

Section 600.300  Illinois Energy Conservation Code

 

a)         The 2021 IECC, including published errata but excluding published supplements, available from the International Code Council at 200 Massachusetts Ave, NW Suite 250, Washington, DC  20001, phone:  1-888-ICC-SAFE (422-7233), www.iccsafe.org, is hereby incorporated into the Illinois Energy Conservation Code, as described in this Subpart as applicable to privately funded commercial facilities, with the modifications outlined in subsection (c).

 

b)         All incorporations by reference in this Section are of the cited standards as they existed on the date specified.  These incorporations include no later editions or amendments.

 

c)         Modifications to IECC

Under Section 15 of the EEB Act, when applying the Illinois Energy Conservation Code to privately funded commercial facilities, CDB may modify the incorporated standards to respond to the unique economy, population distribution, geography and climate of Illinois, as long as the objectives of the EEB Act are maintained. Modifications, additions or omissions to IECC are specified in Appendix A and are rules of the CDB and are not requirements of the IECC.

 

(Source:  Amended at 48 Ill. Reg. 14276, effective January 1, 2025)

 

Section 600.305  Illinois Commercial Stretch Energy Code

 

a)         The 2024 IECC Final Draft, including published errata but excluding published supplements, available from the Capital Development Board, 401 S. Spring St., 3^rd Floor, Springfield, IL  62706 (cdb.energycodes@illinois.gov) through copyright agreement with International Code Council at 200 Massachusetts Ave, NW Suite 250, Washington, DC  20001, phone: 1-888-ICC-SAFE (422-7233), www.iccsafe.org, is hereby incorporated into the Illinois Commercial Stretch Energy Code, as described in this Subpart as applicable to privately funded commercial facilities, with the modifications outlined in subsection (c).

 

b)         All incorporations by reference in this Section are of the cited standards as they existed on the date specified.  These incorporations include no later editions or amendments.

 

c)         Modifications to the IECC

Under Section 55 of the EEB Act, when applying the Illinois Commercial Stretch Energy Code to privately funded commercial facilities, CDB may modify the incorporated standards to meet objectives outlined in the EEB Act.  Modifications, additions or omissions to the IECC Final Draft are specified in Appendix B and are rules of the CDB and are not requirements of the IECC.

 

(Source:  Added at 48 Ill. Reg. 14276, effective January 1, 2025)

 

Section 600.310  Exemptions

 

a)         The following buildings are exempt from the Code:

 

1)         Buildings otherwise exempt from the provisions of a locally adopted building code and buildings that do not contain a conditioned space;

 

2)         Buildings that do not use either electricity or fossil fuel for comfort conditioning;

 

3)         Historic buildings listed on the National Register of Historic Places or the Illinois Register of Historic Places, and those buildings that are designated by authorized personnel as historically significant;

 

4)         Other buildings specified as exempt by the IECC.

 

b)         For the purposes of determining whether an exemption authorized under subsection (a)(2) applies, a building will be presumed to be heated by electricity, even in the absence of equipment used for electric comfort heating, whenever the building is provided with electrical service in excess of 100 amps, unless the code enforcement official determines that this electrical service is necessary for purposes other than providing electric comfort heating. [20 ILCS 3125/20]

 

(Source:  Amended at 43 Ill. Reg. 8707, effective August 5, 2019)

 

Section 600.320  Local Jurisdiction

 

a)         Construction projects involving privately funded commercial facilities and for which a municipality or county requires a building permit must comply with the Illinois Energy Conservation Code or the Illinois Stretch Energy Code if adopted by the municipality if the project involves new construction, addition, alteration, renovation or repair.  In the case of any addition, alteration, renovation or repair to an existing commercial structure, the Code as described by this Subpart C applies only to the portions of that structure that are being added, altered, renovated or repaired. [20 ILCS 3125/20(a)]

 

b)         The local authority having jurisdiction (AHJ) shall establish its own procedures for enforcement of the Illinois Energy Conservation Code and/or the Illinois Commercial Stretch Energy Code.  The AHJ is authorized to enforce an energy code that differs with the Illinois Energy Conservation Code or the Illinois Commercial Stretch Energy Code as described in this Subpart C, but any standards applied by an AHJ must be at least as stringent as the Code as described in this Subpart C.

 

c)         A unit of local government that does not regulate energy efficient building standards is not required to adopt, enforce or administer the Code; however, any energy efficient building standards adopted by a unit of local government must comply with the Act.  If a unit of local government does not regulate energy efficient building standards, any construction, renovation or addition to buildings or structures is still subject to the provisions contained in the Act.  [20 ILCS 3125/20(d)]

 

(Source:  Amended at 48 Ill. Reg. 14276, effective January 1, 2025)

 

Section 600.330  Compliance

 

a)         Compliance with the Illinois Energy Conservation Code as described by this Subpart C (applicable to commercial facilities) shall be determined by the local authority having jurisdiction (AHJ).  Minimum compliance shall be demonstrated by submission of one of the following:

 

1)         The compliance forms published in the ASHRAE 90.1 User's Manual; or

 

2)         Compliance Certificates generated by the U.S. Department of Energy's COMcheck code compliance tool; or

 

3)         Other comparable compliance materials that meet or exceed, as determined by the authority having jurisdiction, the compliance forms published in the ASHRAE 90.1 User's Manual or the U.S. Department of Energy's COMcheck code compliance tool; or

 

4)         The seal of the architect/engineer as required by Section 14 of the Illinois Architecture Practice Act [225 ILCS 305], Section 12 of the Structural Engineering Licensing Act [225 ILCS 340] and Section 14 of the Illinois Professional Engineering Practice Act [225 ILCS 325].

 

b)         Compliance with the Illinois Commercial Stretch Energy Code as described by this Subpart C (applicable to commercial facilities) shall be determined by the local authority having jurisdiction (AHJ).  Minimum compliance shall be demonstrated by submission of one of the following:

 

1)         Buildings certified in compliance with Passive House Institute (PHI) or Passive House Institute U.S. (PHIUS) programs; or

 

2)         Compliance Certificates generated by the U.S. Department of Energy's COMcheck code compliance tool; or

 

3)         The code official shall be permitted to approve specific computer software, worksheets, compliance manuals and other similar materials that meet the intent of this code; or

 

4)         The seal of the architect/engineer as required by Section 14 of the Illinois Architecture Practice Act [225 ILCS 305], Section 12 of the Structural Engineering Licensing Act [225 ILCS 340] and Section 14 of the Illinois Professional Engineering Practice Act [225 ILCS 325].

 

(Source:  Amended at 48 Ill. Reg. 14276, effective January 1, 2025)

 

Section 600.340  Application to Home Rule Units

 

Section 45(d) of the EEB Act is a denial and limitation of home rule powers and functions under subsection (i) of Section 6 of Article VII of the Illinois Constitution on the concurrent exercise by home rule units of powers and functions exercised by the State. Nothing in Section 45(d) of the EEB Act, however, prevents a unit of local government from adopting an energy efficiency code or standards for commercial buildings that are more stringent than the Code under the EEB Act. [20 ILCS 3125/45(d)]

 

(Source:  Amended at 47 Ill. Reg. 17974, effective November 27, 2023)

 

Section 600.400  Illinois Energy Conservation Code

 

a)         The 2021 IECC, including published errata but excluding published supplements, available from the International Code Council at 200 Massachusetts Ave, NW Suite 250, Washington, DC  20001, phone:  1-888-ICC-SAFE (422-7233), www.iccsafe.org, is hereby incorporated into the Illinois Energy Conservation Code, as described in this Subpart as applicable to residential buildings, with the modifications outlined in subsection (c).

 

b)         All incorporations by reference in this Section are of the cited standards as they existed on the date specified.  These incorporations include no later editions or amendments.

 

c)         Modifications to IECC

Under Section 15 of the EEB Act, when applying the Illinois Energy Conservation Code to residential buildings, CDB may modify the incorporated standards to respond to the unique economy, population distribution, geography and climate of Illinois, as long as the objectives of the Act are maintained pursuant to that statutory authority. Modifications, additions or omissions to IECC are specified in Appendix A and are rules of the CDB and are not requirements of the IECC.

 

(Source:  Amended at 48 Ill. Reg. 14276, effective January 1, 2025)

 

Section 600.405  Illinois Residential Stretch Energy Code

 

a)         The 2021 IECC, including published errata but excluding published supplements available from the International Code Council at 500 New Jersey Avenue NW, 6^th Floor, Washington, DC  20001, phone: 1-888-ICC-SAFE (422-7233), www.iccsafe.org, is hereby incorporated into the Illinois Residential Stretch Energy Code, as described in this Subpart as applicable to residential buildings, with modifications outlined in subsection (c).

 

b)         All incorporations by reference in this Section are of the cited standards as they existed on the date specified.  These incorporations include no later editions or amendments.

 

c)         Modifications to the IECC

Under Section 55 of the EEB Act, when applying the Residential Stretch Energy Code to privately funded residential buildings, CDB may modify the incorporated standards to meet objectives outlined in the EEB Act.  Modifications, additions or omissions to the IECC are specified in Appendix C and are rules of the CDB and are not requirements of the IECC.

 

(Source:  Added at 48 Ill. Reg. 14276, effective January 1, 2025)

 

Section 600.410  Exemptions

 

a)         The following buildings are exempt from the Code:

 

1)         Buildings otherwise exempt from the provisions of a locally adopted building code and buildings that do not contain a conditioned space;

 

2)         Buildings that do not use either electricity or fossil fuel for comfort conditioning;

 

3)         Historic buildings listed on the National Register of Historic Places or the Illinois Register of Historic Places, and those buildings that are designated by authorized personnel as historically significant;

 

4)         Other buildings specified as exempt by the IECC. [20 ILCS 3125/20]

 

b)         For the purposes of determining whether an exemption authorized under subsection (a)(2) applies, a building will be presumed to be heated by electricity, even in the absence of equipment used for electric comfort heating, whenever the building is provided with electrical service in excess of 100 amps, unless the code enforcement official determines that this electrical service is necessary for purposes other than providing electric comfort heating. [20 ILCS 3125/20(b)(2)]

 

(Source:  Added at 34 Ill. Reg. 11398, effective July 26, 2010)

 

Section 600.420  Local Jurisdiction

 

a)         Construction projects involving residential buildings and for which a municipality or county requires a building permit must comply with the Illinois Energy Conservation Code or the Illinois Residential Stretch Energy Code if adopted by the municipality if the project involves new construction, addition, alteration, renovation or repair.  In the case of any addition, alteration, renovation or repair to an existing residential structure, the Code as described by this Subpart D applies only to the portions of that structure that are being added, altered, renovated or repaired. [20 ILCS 3125/20(a)]

 

b)         The local authority having jurisdiction (AHJ) shall establish its own procedures for enforcement of the Code. 

 

c)         A unit of local government that does not regulate energy efficient building standards is not required to adopt, enforce or administer the Code; however, any energy efficient building standards adopted by a unit of local government must comply with the Act.  If a unit of local government does not regulate energy efficient building standards, any construction, renovation or addition to buildings or structures is still subject to the provisions contained in the Act. [20 ILCS 3125/20(d)].

 

(Source:  Amended at 48 Ill. Reg. 14276, effective January 1, 2025)

 

Section 600.430  Compliance

 

a)         Compliance with the Illinois Energy Conservation Code as described by this Subpart D (applicable to residential buildings) shall be determined by the local AHJ. Minimum compliance shall be demonstrated by submission of one of the following:

 

1)         Compliance Certificates generated by the U.S. Department of Energy's REScheck code compliance tool; or

 

2)         Other comparable compliance materials that meet or exceed, as determined by the AHJ, U.S. Department of Energy's REScheck code compliance tool; or

 

3)         The seal of the architect/engineer as required by Section 14 of the Illinois Architecture Practice Act [225 ILCS 305], Section 12 of the Structural Engineering Licensing Act [225 ILCS 340] and Section 14 of the Illinois Professional Engineering Practice Act [225 ILCS 325].

 

b)         Compliance with the Illinois Residential Stretch Energy Code as described by this Subpart D (applicable to residential buildings) shall be determined by the local AHJ.  Minimum compliance shall be demonstrated by submission of one of the following:

 

1)         Buildings certified in compliance with Passive House Institute (PHI) or Passive House Institute U.S. (PHIUS) programs; or

 

2)         Compliance Certificates generated by the U.S. Department of Energy's REScheck code compliance tool; or

 

3)         The code official shall be permitted to approve specific computer software, worksheets, compliance manuals and other similar materials that meet the intent of this Code; or

 

4)         The seal of the architect/engineer as required by Section 14 of the Illinois Architecture Practice Act [225 ILCS 305], Section 12 of the Structural Engineering Licensing Act [225 ILCS 340] and Section 14 of the Illinois Professional Engineering Practice Act [225 ILCS 325].

 

(Source:  Amended at 48 Ill. Reg. 14276, effective January 1, 2025)

 

Section 600.440  Application to Home Rule Units

 

a)         No unit of local government, including any home rule unit, may regulate energy efficient building standards for residential buildings in a manner that is either less or more stringent than the standards established in this Subpart D.

 

b)         The following entities may regulate energy efficient building standards for residential or commercial buildings in a manner that is more stringent than the provisions contained in this Subpart D:

 

1)         A unit of local government, including a home rule unit, that has, on or before May 15, 2009, adopted or incorporated by reference energy efficient building standards for residential or commercial buildings that are equivalent to or more stringent than the 2006 IECC.

 

2)         A unit of local government, including a home rule unit, that has, on or before May 15, 2009, provided to the Capital Development Board, as required by Section 10.18 of the Capital Development Board Act [20 ILCS 3105], an identification of an energy efficient building code or amendment that is equivalent to or more stringent than the 2006 IECC.

 

3)         A municipality with a population of 1,000,000 or more; and

 

4)         A municipality that has adopted the Illinois Stretch Energy Code [20 ILCS 3125/45(b)].

 

c)         No unit of local government, including any home rule unit or unit of local government that is subject to State regulation under the Code as provided in Section 15 of the EEB may enact any annexation ordinance or resolution, or require or enter into any annexation agreement, that imposes energy efficient building standards for residential or commercial buildings that are either less or more stringent than the energy efficiency standards in effect, at the time of construction, throughout the unit of local government, except for the Illinois Stretch Energy Code. [20 ILCS 3125/45(c)]

 

(Source:  Amended at 48 Ill. Reg. 14276, effective January 1, 2025)

Section 600.APPENDIX A   Illinois Energy Conservation Code Amendments to the 2021 International Energy Conservation Code

 

The following Code sections shall be referenced in place of the corresponding 2021 IECC sections.

 

CHAPTER 1 [CE]

SCOPE AND ADMINISTRATION

 

SECTION C101

SCOPE AND GENERAL REQUIREMENTS

 

C101.1  Title.  This Code shall be known as the 2021 Illinois Energy Conservation Code or Code and shall mean:

 

With respect to the State facilities covered by 71 Ill. Adm. Code 600.Subpart B:

 

This Part, all additional requirements incorporated within Subpart B (including the 2021 International Energy Conservation Code, including all published errata but excluding published supplements that encompass ASHRAE 90.1-2019), and any statutorily authorized adaptations to the incorporated standards adopted by CDB, are effective January 1, 2024.

 

With respect to the privately funded commercial facilities covered by 71 Ill. Adm. Code 600.Subpart C:

 

This Part, all additional requirements incorporated within Subpart C (including the 2021 International Energy Conservation Code, including all published errata and excluding published supplements that encompass ASHRAE 90.1-2019), and any statutorily authorized adaptations to the incorporated standards adopted by CDB, are effective January 1, 2024.

 

C101.1.1  Adoption.  The Board shall adopt amendments to this Code within 12 months after publication of the 2021 International Energy Conservation Code. Any such update in this Code shall take effect within 6 months after it is adopted by the Board and shall apply to any new building or structure in this State for which a building permit application is received by a municipality or county, except as otherwise provided by the EEB Act.

 

C101.1.2  Adaptation.  The Board may appropriately adapt the International Energy Conservation Code to apply to the particular economy, population distribution, geography and climate of the State and construction within the State, consistent with the public policy objectives of the EEB Act.

 

C101.5  Compliance.  Commercial buildings shall meet the provisions of the Illinois Energy Conservation Code covered by 71 Ill. Adm. Code 600.Subpart C.  The local authority having jurisdiction (AHJ) shall establish its own procedures for enforcement of the Illinois Energy Conservation Code.  Minimum compliance shall be demonstrated by submission of:

 

1.         Compliance forms published in the ASHRAE 90.1 User's Manual; or

 

2.         Compliance Certificates generated by the U.S. Department of Energy's COMcheck^TM Code compliance tool; or

 

3.         Other comparable compliance materials that meet or exceed, as determined by the AHJ, the compliance forms published in the ASHRAE 90.1 User's Manual or the U.S. Department of Energy's COMcheck^TM code compliance tool; or

 

4.         The seal of the architect/engineer as required by Section 14 of the Illinois Architectural Practice Act [225 ILCS 305], Section 12 of the Structural Engineering Licensing Act [225 ILCS 340] and Section 14 of the Illinois Professional Engineering Practice Act [225 ILCS 325].

 

C102.1.1  Above code programs.  No unit of local government, including any home rule unit, may apply energy efficient building standards to privately funded commercial facilities in a manner that is less stringent than this Code as described in 71 Ill. Adm. Code 600.Subpart C.  However, nothing in the EEB Act or Subpart C prevents a unit of local government from adopting an energy efficiency code or standards that are more stringent than this Code.  The requirements identified in Table C407.2 shall be met.

 

SECTION C110

BOARD OF APPEALS

 

C110.1  General.  In order to hear and decide appeals of orders, decisions or determinations made by the code official relative to the application and interpretation of this Code, there may be created a board of appeals.  The code official shall be an ex officio member of the board of appeals but shall not have a vote on any matter before the board.  The board of appeals shall be appointed by the governing body and shall hold office at its pleasure.  The board shall adopt rules of procedure for conducting its business and shall render all decisions and findings in writing to the appellant with a duplicate copy to the code official.

 

C110.3  Qualifications.  The board of appeals shall consist of members who are qualified by experience and training.

 

CHAPTER 2 [CE]

DEFINITIONS

 

SECTION C202

GENERAL DEFINITIONS

 

APPROVED SOURCE. An independent person, firm, or corporation, approved by the building official, who is competent and experienced in the application of engineering principles to materials, methods or systems analyses.

 

AUTHORITY HAVING JURISDICTION (AHJ). The organization, officer or individual responsible for approving equipment, materials, an installation or procedure.

 

BOARD. The Illinois Capital Development Board.

 

COUNCIL. The Illinois Energy Conservation Advisory Council whose purpose is to recommend modifications to the Illinois Energy Conservation Code.

 

DEMAND RESPONSE SIGNAL. A signal that indicates a price or a request to modify electricity consumption for a limited time period.

 

DEMAND RESPONSIVE CONTROL. A control capable of receiving and automatically responding to a demand response signal.

 

EEB ACT. The Energy Efficient Building Act [20 ILCS 3125].

 

PHOTOSYNTHETIC PHOTON EFFICACY (PPE). A photosynthetic photon flux divided by input electric power in units of micromoles per second per watt, or micromoles per joule as defined by ANSI/ASABE S640.

 

CHAPTER 4 [CE]

COMMERCIAL ENERGY EFFICIENCY

 

SECTION C402

BUILDING ENVELOPE REQUIREMENTS

 

C402.4.1.3  Fenestration orientation

The vertical fenestration shall comply with either equation a. or b.:

a.         AW ≤ (AT)/4 and AE ≤ (AT)/4

b.         AW × SHGCW ≤ (AT × SHGCC)/5 and AE × SHGCE ≤ (AT × SHGCC)/5

 

where:

 

AW = West-oriented vertical fenestration area (oriented within 45 degrees of true west to the south and within 22.5 degrees of true west to the north in the Northern Hemisphere)

 

AE = East-oriented vertical fenestration area (oriented within 45 degrees of true east to the south and within 22.5 degrees of true east to the north in the Northern Hemisphere)

 

AT = Total vertical fenestration area

 

SHGCC = SHGC criteria in Table C402.4

 

SHGCE = SHGC for east-oriented fenestration

 

SHGCW = SHGC for west-oriented fenestration

 

Exceptions:

 

1.         Buildings with shade on 75% of the east-oriented and west-oriented vertical fenestration areas from permanent projections, existing buildings, existing permanent infrastructure, or topography at 9 a.m. and 3 p.m., respectively, on the summer solstice (June 21).

 

2.         Alterations and additions with no increase in vertical fenestration area.

 

3.         Buildings where the east-oriented and west-oriented vertical fenestration area does not exceed 20% of the gross wall area for each of those façades, and SHGC on those facades is no greater than 90% of the criteria in Table C402.4.

 

C402.5.1  Air barriers. A continuous air barrier shall be provided throughout the building thermal envelope. The air barriers shall be permitted to be located on the inside or outside of the building envelope, located within the assemblies composing the envelope, or any combination thereof. The air barrier shall comply with Sections C402.5.1.1 and C402.5.1.2.  For roof air barriers on existing buildings, refer to Section C503.1 or C504.2.

 

Exception:  Air barriers are not required in buildings located in Climate Zone 2B.

 

C402.5.1.1  Air barrier construction. The continuous air barrier shall be constructed to comply with the following:

 

1.         The air barrier shall be continuous for all assemblies that are the thermal envelope of the building and across the joints and assemblies.

 

2.         Air barrier joints and seams shall be sealed, including sealing transitions at joints between dissimilar materials. The joints and seals shall be securely installed in or on the joint for its entire length so as not to dislodge, loosen or otherwise impair its ability to resist positive and negative pressure from wind, stack effect and mechanical ventilation.

 

3.         Penetrations of the air barrier shall be caulked, gasketed or otherwise sealed in a manner compatible with the construction materials and location. Sealings shall allow for expansion, contraction and mechanical vibration. Paths for air leakage from the building to the space between the roof deck and roof covering used as an air barrier shall be caulked, gasketed or otherwise covered with a moisture vapor-permeable material. Joints and seams associated with penetrations shall be sealed in the same manner or taped. Sealing materials shall be securely installed around the penetration so as not to dislodge, loosen or otherwise impair the penetrations' ability to resist positive and negative pressure from wind, stack effect and mechanical ventilation. Sealing of concealed fire sprinklers, where required, shall be in a manner that is recommended by the manufacturer. Caulking or other adhesive sealants shall not be used to fill voids between fire sprinkler cover plates and walls or ceilings.

 

4.         Recessed lighting fixtures shall comply with Section C402.5.10. Where similar objects are installed that penetrate the air barrier, provisions shall be made to maintain the integrity of the air barrier.

 

SECTION C405

ELECTRICAL POWER AND LIGHTING SYSTEMS

 

C405.4  Lighting for plant growth and maintenance. All permanently installed luminaires used for plant growth and maintenance shall have a photosynthetic photon efficacy, as defined in accordance with ANSI/ASABE S640, of not less than 1.7 μmol/J for greenhouses and not less than 2.2 μmol/J for all other indoor growing spaces.

 

Exception: The following buildings are exempt:

 

1.         Buildings with no more than 40kW of aggregate horticultural lighting load.

 

2.         Cannabis facilities subject to 410 ILCS 705/10-45, the Cannabis Regulation and Tax Act.

 

SECTION C406

ADDITIONAL EFFICIENCY REQUIREMENTS

 

C406.1  Additional energy efficiency credit requirements. New buildings shall achieve a total of 10 credits from Tables C406.1(1) through C406.1(5) where the table is selected based on the use group of the building and from credit calculations as specified in relevant subsections of Section C406. Where a building contains multiple-use groups, credits from each use group shall be weighted by floor area of each group to determine the weighted average building credit. Credits from the tables or calculation shall be achieved where a building complies with one or more of the following:

 

1.         More efficient HVAC performance in accordance with Section C406.2.

 

2.         Reduced lighting power in accordance with Section C406.3.

 

3.         Enhanced lighting controls in accordance with Section C406.4.

 

4.         On-site supply of renewable energy in accordance with Section C406.5.

 

5.         Provision of a dedicated outdoor air system for certain HVAC equipment in accordance with Section C406.6.

 

6.         High-efficiency service water heating in accordance with Section C406.7.

 

7.         Enhanced envelope performance in accordance with Section C406.8.

 

8.         Reduced air infiltration in accordance with Section C406.9

 

9.         Where not required by Section C405.12, include an energy monitoring system in accordance with Section C406.10.

 

10.       Where not required by Section C403.2.3, include a fault detection and diagnostics (FDD) system in accordance with Section C406.11.

 

11.       Efficient kitchen equipment in accordance with Section C406.12.

 

12.       HVAC demand responsive controls and more efficient HVAC performance in accordance with Sections C406.2 and C406.13.

 

13.       Water-heating demand responsive controls and high-efficiency service water heating in accordance with Sections C406.7 and C406.14.

 

Modify Table C406.1(1) as follows:

 

Table C406.1(1) Additional Energy Efficiency Credits for Group B Occupants

 

Modify Table C406.1(2) as follows:

 

Table C406.1(2) Additional Energy Efficiency Credits for Group R and I Occupancies

 

 

Modify Table C406.1(3) as follows:

 

Table C406.1(3) Additional Energy Efficiency Credits for Group E Occupancies

 

 

Modify Table C406.1(4) as follows:

 

Table C406.1(4) Additional Energy Efficiency Credits for Group M Occupancies

 

 

Modify Table C406.1(5) as follows:

 

Table C406.1(5) Additional Energy Efficiency Credits for Other* Occupancies

 

 

C406.1.1  Tenant spaces. Tenant spaces shall comply with sufficient options from Tables C406.1(1) through C406.1(5) to achieve a minimum number of 5 credits, where credits are selected from Section C406.2, C406.3, C406.4, C406.6, C406.7 or C406.10. Where the entire building complies using credits from Section C406.5, C406.8, C406.9 or C406.13 tenant spaces shall be deemed to comply with this section.

 

C406.13 HVAC demand responsive controls. Buildings shall be provided with demand responsive controls capable of executing the following actions in response to a demand response signal:

1.         Automatically increasing the zone operating cooling set point by the following values: 1°F (0.5°C), 2°F (1°C), 3°F (1.5°C), and 4°F (2°C).

2.         Automatically decreasing the zone operating heating set point by the following values: 1°F (0.5°C), 2°F (1°C), 3°F (1.5°C), and 4°F (2°C).

 

Where a demand response signal is not available, the heating and cooling system controls shall be capable of performing all other functions. Where thermostats are controlled by direct digital control, including but not limited to, an energy management system, the system shall be capable of demand responsive control and capable of adjusting all thermal setpoints to comply. The demand responsive controls shall comply with either Section C406.13.1 or C406.13.2.

 

C406.13.1Air conditioners and heat pumps with two or more stages of control and cooling capacity of less than 65,000 Btu/h. Thermostats for air conditioners and heat pumps with two or more stages of control and a cooling capacity less than 65,000 Btu/h (19 kW) shall be provided with a demand responsive control that complies with the communication and performance requirements of AHRI 1380.

 

C406.13.2 All other HVAC systems. Thermostats for HVAC systems shall be provided with a demand responsive control that complies with one of the following:

1.         Certified OpenADR 2.0a VEN, as specified under Clause 11, Conformance.

2.         Certified OpenADR 2.0b VEN, as specified under Clause 11, Conformance.

3.         Certified by the manufacturer as being capable of responding to a demand response signal from a certified OpenADR 2.0b VEN by automatically implementing the control functions requested by the VEN for the equipment it controls.

4.         IEC 62746-10-1.

5.         The communication protocol required by a controlling entity, such as a utility or service provider, to participate in an automated demand response program.

6.         The physical configuration and communication protocol of CTA 2045-A or CTA 2045-B.

 

C406.14 Water-heating demand responsive controls. Electric storage water heaters with a rated water storage volume of 40 to 120 gallons (150 to 450 L) and a nameplate input rating equal to or less than 12kW shall be provided with demand responsive controls in accordance with Table C406.14 or another equivalent approved standard.

 

Table C406.14

Demand Responsive CONTROLS FOR Water Heating

Equipment Type	Controls
Electric storage water heaters	Manufactured before 7/1/2025	Manufactured on or after 7/1/2025
	ANSI/CTA-2045-B Level 1 and also capable of initiating water heating to meet the temperature set point in response to a demand response signal.	ANSI/CTA-2045-B Level 2, except “Price Stream Communication” functionality as defined in the standard.

 

SECTION C407

TOTAL BUILDING PERFORMANCE

 

Modify Table C407.2 as follows:

 

TABLE C407.2

REQUIREMENTS FOR TOTAL BUILDING PERFORMANCE

SECTIONa	TITLE
Envelope
C402.4.1.3	Fenestration orientation

 

Modify Table C407.4.1(1) as follows:

 

TABLE C407.4.1(1)

SPECIFICATIONS FOR THE STANDARD REFERENCE AND PROPOSED DESIGNS

Vertical fenestration other than opaque doors	Area 1. The proposed vertical fenestration area; where the proposed vertical fenestration area is less than 40 percent of the above-grade wall area. 2. 40 percent of the above grade wall area; where the proposed vertical fenestration area is 40 percent or more of the above grade wall area 3. Fenestration orientation shall comply with Section C402.4.1.3.	As proposed
	U-factor: as specified in Table C402.4	As proposed
	1. SHGC: as specified in Table C402.4, except that for climates with no requirement (NR) SHGC = 0.40 shall be used. 2. Fenestration SHGC shall comply with Section C402.4.1.3	As proposed
	External shading and PF: none	As proposed

 

CHAPTER 5 [CE]

EXISTING BUILDINGS

 

SECTION C503

ALTERATIONS

 

C503.2.1 Roof replacement. Roof replacements shall comply with Section C402.1.3, C402.1.4, C402.1.5 or C407 where the existing roof assembly is part of the building thermal envelope and contains insulation entirely above the roof deck.  In no case shall the R-value of the roof insulation be reduced or the U-factor of the roof assembly be increased as part of the roof replacement.

 

Exceptions: Where compliance with Section C402.1 cannot be met due to limiting conditions on an existing roof, an approved design shall be submitted with the following:

 

1.         Construction documents that include a report by a registered design professional or an approved source documenting details of the limiting conditions affecting compliance with the insulation requirements.

 

2.         Construction documents that include a roof design by a registered design professional or an approved source that minimizes deviation from the insulation requirements.

 

Chapter 6 [CE]

Referenced Standards

 

ASME	ASME Two Park Avenue New York, NY  10016-5990
AHRI	Air-Conditioning, Heating, & Refrigeration Institute 2111 Wilson Blvd, Suite 500 Arlington, VA  22201
1380-2019	Demand Response through Variable Capacity HVAC Systems in Residential and Small Commercial Applications C406.13.1
ANSI	American National Standards Institute 25 West 43rd Street, 4th Floor New York, NY  10036
ANSI/CTA-2045-A-2018	Modular Communications Interface for Energy Management
ANSI/CTA-2045-B-2019	Modular Communications Interface for Energy Management
CTA	Consumer Technology Association 1919 S. Eads Street Arlington, VA  22202
ANSI/CTA-2045-B	Modular Communications Interface for Energy Management C404.11
IEC	IEC Regional Centre for North America IEC International Electrotechnical Commission 446 Main Street 16th Floor Worcester, MA  01608
IEC 62746-10-1 - 2018	Systems Interface Between Customer Energy Management Systems and the Power Management Systems – Part 10-1: Open Automated Demand Response C406.13.2 (4).

 

CHAPTER 1 [RE]

SCOPE AND ADMINISTRATION

 

SECTION R101

SCOPE AND GENERAL REQUIREMENTS

 

R101.1  Title.  This Code shall be known as the 2021 Illinois Energy Conservation Code or Code and shall mean:

 

With respect to the residential buildings covered by 71 Ill. Adm. Code 600.Subpart D:

 

This Part, all additional requirements incorporated within Subpart D (including the 2021 International Energy Conservation Code, including all published errata but excluding published supplements) and any statutorily authorized adaptations to the incorporated standards adopted by CDB are effective January 1, 2024.

 

R101.1.1  Adoption.  The Board shall adopt amendments to this Code within 12 months after publication of the 2021 International Energy Conservation Code. Any such update in this Code shall take effect within 6 months after it is adopted by the Board and shall apply to any new building or structure in this State for which a building permit application is received by a municipality or county, except as otherwise provided by the EEB Act.

 

R101.1.2  Adaptation.  The Board may appropriately adapt the International Energy Conservation Code to apply to the particular economy, population distribution, geography and climate of the State and construction within the State, consistent with the public policy objectives of the EEB Act.

 

R101.5  Compliance.  Residential buildings shall meet the provisions of the Illinois Energy Conservation Code covered by 71 Ill. Adm. Code 600.Subpart D.  The local authority having jurisdiction (AHJ) shall establish its own procedures for enforcement of the Illinois Energy Conservation Code.  Minimum compliance shall be demonstrated by submission of:

 

1.         Compliance Certificates generated by the U.S. Department of Energy's REScheck^TM Code compliance tool; or

 

2.         Other comparable compliance materials that meet or exceed, as determined by the AHJ, U.S. Department of Energy's REScheck^TM Code compliance tool; or

 

3.         The seal of the architect/engineer as required by Section 14 of the Illinois Architectural Practice Act [225 ILCS 305], Section 12 of the Structural Engineering Licensing Act [225 ILCS 340] and Section 14 of the Illinois Professional Engineering Practice Act [225 ILCS 325].

 

SECTION R102

ALTERNATIVE MATERIALS DESIGN AND METHODS

OF CONSTRUCTION AND EQUIPMENT

 

R102.1.1  Above code programs.  No unit of local government, including any home rule unit, may regulate energy efficient building standards for residential buildings in a manner that is either less or more stringent than the standards established pursuant to this Code.  Buildings shall be considered to be in compliance with this code where such buildings also meet the requirements identified in Table R405.2 and the building thermal envelope is greater than or equal to levels of efficiency and solar heat gain coefficients (SHGC) in Tables 402.1.1 and 402.1.3 of the 2009 International Energy Conservation Code.

 

However, the following entities may regulate energy efficient building standards for residential buildings in a manner that is more stringent than the provisions contained in this Code:

 

1.         A unit of local government, including a home rule unit, that has, on or before May 15, 2009, adopted or incorporated by reference energy efficient building standards for residential buildings that are equivalent to or more stringent than the 2006 International Energy Conservation Code.

 

2.         A unit of local government, including a home rule unit, that has, on or before May 15, 2009, provided to the Capital Development Board, as required by Section 10.18 of the Capital Development Board Act, an identification of an energy efficient building code or amendment that is equivalent to or more stringent than the 2006 International Energy Conservation Code.

 

3.         A municipality with a population of 1,000,000 or more.

 

4.         A municipality that has adopted the Illinois Stretch Energy Code.

 

SECTION R110

MEANS OF APPEALS

 

R110.1  General.  In order to hear and decide appeals of orders, decisions or determinations made by the code official relative to the application and interpretation of this Code, there may be created a board of appeals.  The code official shall be an ex officio member of the board of appeals but shall not have a vote on any matter before the board.  The board of appeals shall be appointed by the governing body and shall hold office at its pleasure.  The board shall adopt rules of procedure for conducting its business and shall render all decisions and findings in writing to the appellant with a duplicate copy to the code official.

 

R110.3  Qualifications.  The board of appeals shall consist of members who are qualified by experience and training.

 

CHAPTER 2 [RE]

DEFINITIONS

 

SECTION R202

GENERAL DEFINITIONS

 

APPROVED SOURCE. An independent person, firm, or corporation, approved by the building official, who is competent and experienced in the ap-plication of engineering principles to materials, methods or systems analyses.

 

AUTHORITY HAVING JURISDICTION (AHJ). The organization, officer or individual responsible for approving equipment, materials, an installation or procedure.

 

BOARD. The Illinois Capital Development Board.

 

COUNCIL. The Illinois Energy Conservation Advisory Council whose purpose is to recommend modifications to the Illinois Energy Conservation Code.

 

EEB ACT. The Energy Efficient Building Act [20 ILCS 3125].

 

LOCAL EXHAUST. An exhaust system that uses one or more fans to exhaust air from a specific room or rooms within a dwelling.

 

RESIDENTIAL BUILDING. A detached one-family or two-family dwelling or any building that is three stories or less in height above grade that contains multiple dwelling units, in which the occupants reside on a primarily permanent basis, such as a townhouse, a row house, an apartment house, a convent, a monastery, a rectory, a fraternity or sorority house, a dormitory and a rooming house;  provided, however, that when applied to a building located within the boundaries of a municipality having a population of 1,000,000 or more, the term "residential building" means a building containing one or more dwelling units, not exceeding four stories above grade, where occupants are primarily permanent.

 

WHOLE-HOUSE MECHANICAL VENTILATION SYSTEM. An exhaust system, supply system or combination thereof that is designed in accordance with Section R403.6 to mechanically exchange indoor air with outdoor air when operating continuously or through a programmed intermittent schedule to satisfy the whole-house ventilation rates.  Outdoor air intakes and exhausts shall have automatic or gravity dampers that close when the ventilation system is not operating.

 

CHAPTER 4 [RE]

RESIDENTIAL ENERGY EFFICIENCY

 

SECTION R401

GENERAL

 

R401.2  Application. Residential buildings shall comply with Section R401.2.6 and either Sections R401.2.1, R401.2.2, R401.2.3, R401.2.4 or R401.2.5.

 

Exception: Additions, alterations, repairs and changes of occupancy to existing buildings complying with Chapter 5.

 

R401.2.5  Phius alternative compliance option.  The Phius Alternative Compliance Option requires compliance with Section R409.

 

R401.2.6  Additional energy efficiency. This Section establishes additional requirements applicable to all compliance approaches to achieve additional energy efficiency.

 

1.         For buildings complying with Section R401.2.1, one of the additional efficiency package options shall be installed according to Section R408.2.

 

2.         For buildings complying with Section R401.2.2, the building shall meet one of the following:

2.1.  One of the additional efficiency package options in Section R408.2 shall be installed without including such measures in the proposed design under Section R405; or

2.2.  The proposed design of the building under Section R405.2 shall have an annual energy cost that is less than or equal to 95 percent of the annual energy cost of the standard reference design.

 

3.         For buildings complying with the Energy Rating Index alternative Section R401.2.3, the Energy Rating Index value shall be at least 5 percent less than the Energy Rating Index target specified in Table R406.5.

 

The option selected for compliance shall be identified in the certificate required by Section R401.3.

 

SECTION R402

BUILDING THERMAL ENVELOPE

 

Modify Table R402.1.2 as follows:

 

TABLE R402.1.2

MAXIMUM ASSEMBLY U-FACTORS^a AND FENESTRATION REQUIREMENTS

 

 

Modify Table R402.1.3 as follows:

 

TABLE R402.1.3

INSULATION MINIMUM R-VALUES AND FENESTRATION REQUIREMENTS

BY COMPONENTa

 

 

R402.2.1  Roof/ceilings with attics. Where Section R402.1.3 requires R-49 insulation in the ceiling or attic, installing R-38 over 100 percent of the ceiling or attic area requiring insulation shall satisfy the requirement for R-49 insulation wherever the full height of uncompressed R-38 insulation extends over the wall top plate at the eaves. This reduction shall not apply to the insulation and fenestration criteria in Section R402.1.2 and the Total UA alternative in Section R402.1.5.

 

R402.2.2  Roof/ceilings without attics. When Section R402.1.3 requires insulation R-values greater than R-30 in the interstitial space above a ceiling and below the structural roof deck, and the design of the roof/ceiling assembly does not allow sufficient space for the required insulation, the minimum required insulation R-value for those roof/ceiling assemblies shall be R-30. Insulation shall extend over the top of the wall plate to the outer edge of the plate and shall not be compressed. This reduction of insulation from the requirements of Section R402.1.3 shall be limited to 500 square feet (46 m²) or 20 percent of the total insulated ceiling area, whichever is less. This reduction shall not apply to the Total UA alternative in Section R402.1.5.

 

R402.2.8.1  Basement wall insulation installation. Where basement walls are insulated, the insulation shall be installed from the top of the basement wall down to 10 feet (3048 mm) below grade or to within 6 inches (152 mm) of the basement floor, whichever is less.

 

SECTION R403

SYSTEMS

 

R403.3  Ducts.  Ducts and air handlers shall be insulated, sealed, tested and installed in accordance with Sections R403.3.1 through R403.3.7.  When required by the code official, duct testing shall be conducted by an approved third party.  A written report of the results of the test shall be signed by the party conducting the test and provided to the code official. 

 

R403.3.5 Duct testing. 

Ducts shall be pressure tested in accordance with ANSI/RESNET/ICC 380 or ASTM E1554 to determine air leakage by one of the following methods:

 

1.         Rough-in test: Total leakage shall be measured with a pressure differential of 0.1 inch w.g. (25 Pa) across the system, including the manufacturer's air handler enclosure if installed at the time of the test.  Registers shall be taped or otherwise sealed during the test. 

 

2.         Postconstruction test:  Total leakage shall be measured with a pressure differential of 0.1 inch w.g. (25 Pa) across the entire system, including the manufacturer's air handler enclosure.  Registers shall be taped or otherwise sealed during the test. 

 

Exception: A duct air-leakage test shall not be required for ducts serving ventilation systems that are not integrated with ducts serving heating or cooling systems.

 

R403.3.6 Duct leakage.

 

The total leakage of the ducts, where measured in accordance with Section R403.3.5, shall be as follows:

 

1.         Rough-in test: The total leakage shall be less than or equal to 4.0 cubic feet per minute (113.3 L/min) per 100 square feet (9.29 m²) of conditioned floor area where the air handler is installed at the time of the test. Where the air handler is not installed at the time of the test, the total leakage shall be less than or equal to 3.0 cubic feet per minute (85 L/min) per 100 square feet (9.29 m²) of conditioned floor area.

 

Exception: If the HVAC duct system is serving less than or equal to 1,500 square feet (139.4 m²) of conditioned floor area, the allowable duct leakage with the air handler installed shall be 60 cubic feet per minute (1700 L/min) or less.

 

2.         Postconstruction test: Total leakage shall be less than or equal to 4.0 cubic feet per minute (113.3 L/min) per 100 square feet (9.29 m²) of conditioned floor area.

 

Exception: If the HVAC duct system is serving less than or equal to 1,500 square feet (139.4 m²) of conditioned floor area, the allowable duct leakage shall be 60 cubic feet per minute (1700 L/min) or less.

 

3.         Test for ducts within thermal envelope: Where all ducts and air handlers are located entirely within the building thermal envelope, total leakage shall be less than or equal to 8.0 cubic feet per minute (226.6 L/min) per 100 square feet (9.29 m²) of conditioned floor area.

 

Exception: If the HVAC duct system is serving less than or equal to 750 square feet (69.7 m²) of conditioned floor area, the allowable duct leakage with the air handler installed shall be 60 cubic feet per minute (1700 L/min) or less.

 

R403.6 Mechanical ventilation.  The buildings or dwelling units complying with Section R402.4.1 shall be provided with ventilation that complies with the requirements of this section or the International Mechanical Code, as applicable, or with other approved means of ventilation.  Outdoor air intakes and exhausts shall have automatic or gravity dampers that close when the ventilation system is not operating.

 

R403.6.4 Recirculation of air.  Exhaust air from bathrooms and toilet rooms shall not be recirculated within a residence or circulated to another dwelling unit and shall be exhausted directly to the outdoors. Exhaust air from bathrooms, toilet rooms and kitchens shall not discharge into an attic, crawl space or other areas inside the building.  This section shall not prohibit the installation of ductless range hoods when installed in accordance with the manufacturer's instructions, and where mechanical or natural ventilation is otherwise provided, listed and labeled ductless range hoods shall not be required to discharge to the outdoors.

 

R403.6.5 Exhaust equipment.  Exhaust fans and whole-house ventilation fans shall be listed and labeled as providing the minimum required airflow in accordance with ANSI/AMCA 210-ANSI/ASHRAE 51.

 

R403.6.6 Whole-house mechanical ventilation system.  Whole-house mechanical ventilation systems shall be designed in accordance with Sections R403.6.6.1 through R403.6.6.4.

 

R403.6.6.1 System design.  The whole-house ventilation system shall consist of one or more supply or exhaust fans, or a combination of such, and associated ducts and controls. Local exhaust or supply fans are permitted to serve as such a system. Outdoor air ducts connected to the return side of an air handler shall be considered to provide supply ventilation.

 

R403.6.6.2 System controls.  The whole-house mechanical ventilation system shall be provided with controls that enable manual override.  Controls shall include text or a symbol indicating their function.

 

R403.6.6.3 Mechanical ventilation rate.  The whole house mechanical ventilation system shall provide outdoor air at a continuous rate of not less than that determined in accordance with Table R403.6.6.3(1) or Equation 4-0.

 

Ventilation rate in cubic feet per minute = (0.01 x total square foot area of house) + [7.5 x (number of bedrooms +1)] Equation 4-0

 

Exceptions:

 

1.         Ventilation rate credit.  The minimum mechanical ventilation rate determined in accordance with Table R403.6.6.3(1) or Equation 4-0 shall be reduced by 30 percent, provided that both of the following conditions apply:

 

1.1.      A ducted system supplies ventilation air directly to each bedroom and to one or more of the following rooms:

1.1.1.  Living room.

1.1.2  Dining room.

1.1.3  Kitchen.

1.2.      The whole-house ventilation system is a balanced ventilation system.

 

2.         Programmed intermittent operation.  The whole-house mechanical ventilation system is permitted to operate intermittently where the system has controls that enable operation for not less than 25 percent of each 4-hour segment and the ventilation rate in Table R403.6.6.3(1), Equation 4-0 or Exception 1 is multiplied by the factor determined in accordance with Table R403.6.6.3(2).

 

R403.6.6.3.1 Different occupant density.  Table R403.6.6.3(1) assumes 2 persons in a dwelling unit and an additional person for each additional bedroom. When higher occupant densities are known, the airflow rate shall be increased by 7.5 cfm (3.5 L/s) for each additional person. When approved by the authority having jurisdiction, lower occupant densities may be used.

 

R403.6.6.3.2 Airflow measurement.  The airflow rate required is the quantity of outdoor ventilation air supplied and/or indoor air exhausted by the whole-house mechanical ventilation system installed, and shall be measured using a flow hood, flow grid, or other airflow measuring device. Ventilation airflow of systems with multiple operating modes shall be tested in all modes designed to meet Section R403.6.6.3. Where required by the code official, testing shall be conducted by an approved third party. A written report of the results of the test, indicating the verified airflow rate, shall be signed by the party conducting the test and provided to the code official.

 

R403.6.6.4 Local exhaust rates.  Local exhaust systems shall be designed to have the capacity to exhaust the minimum airflow rate determined in accordance with Table R403.6.6.4.

 

TABLE R403.6.6.3(1)

CONTINUOUS WHOLE-HOUSE MECHANICAL

VENTILATION SYSTEM AIRFLOW RATE REQUIREMENTS

 

DWELLING UNIT FLOOR AREA (square feet)	NUMBER OF BEDROOMS
	0 - 1	2 - 3	4 - 5	6 - 7	> 7
	Airflow in cfm
< 1,500	30	45	60	75	90
1,501 - 3,000	45	60	75	90	105
3,001 - 4,500	60	75	90	105	120
4,501 - 6,000	75	90	105	120	135
6,001 - 7,500	90	105	120	135	150
> 7,500	105	120	135	150	165

 

For SI: 1 square foot = 0.0929 m², 1 cubic foot per minute = 0.0004719 m³/s.

 

TABLE R403.6.6.3(2)

INTERMITTENT WHOLE-HOUSE MECHANICAL

VENTILATION RATE FACTORS^{a, b}

 

RUN-TIME PERCENTAGE IN EACH 4-HOUR SEGMENT	25%	33%	50%	66%	75%	100%
Factor a	4	3	2	1.5	1.3	1.0

 

^a     For ventilation system run time values between those given, the factors are permitted to be determined by interpolation.

 

^b     Extrapolation beyond the table is prohibited.

 

TABLE R403.6.6.4

MINIMUM REQUIRED LOCAL EXHAUST RATES FOR

ONE- AND TWO-FAMILY DWELLINGS

 

AREA TO BE EXHAUSTED	EXHAUST RATESa
Kitchens	100 cfm intermittent or 25 cfm continuous
Bathrooms-Toilet Rooms	Mechanical exhaust capacity of 50 cfm intermittent or 20 cfm continuous

 

For SI: 1 cubic foot per minute = 0.0004719 m³/s.

a.         The listed exhaust rate for bathrooms-toilet rooms shall equal or exceed the exhaust rate at a minimum static pressure of 0.25 inch water column, in accordance with Section R403.6.5.

 

Modify Table R405.2 as follows:

 

TABLE R405.2

REQUIREMENTS FOR TOTAL BUILDING PERFORMANCE

 

 

Modify Table R406.2 as follows:

 

TABLE R406.2

REQUIREMENTS FOR ENERGY RATING INDEX

 

 

SECTION R408

ADDITIONAL EFFICIENCY PACKAGE OPTIONS

 

R408.1 Scope.  This section establishes additional efficiency package options to achieve additional energy efficiency in accordance with Section R401.2.6.

 

 

SECTION R409

PHIUS ALTERNATIVE COMPLIANCE OPTION

 

R409.1 Scope.  This section establishes criteria for compliance via the Phius 2021 Standard.

 

R409.2 Phius standard compliance.  Compliance based on the Phius 2021 Standard will include its United States Department of Energy (USDOE) Energy Star and Zero Energy Ready Home corequisites, and either performance calculations by Phius-approved software or through the use of the Phius 2021 Prescriptive Path. 

 

R409.2.1 Phius documentation.  Prior to the issuance of a building permit, the following items must be provided to the code official:

 

1.         A list of compliance features.

2.         A Phius precertification letter.

 

R409.2.2 Project certificate. Prior to the issuance of a certificate of occupancy, a Phius 2021 (or later) project certificate must be provided to the code official.

 

SECTION R503

ALTERATIONS

 

R503.1.1.2 Roof replacement.  Insulation shall comply with Section R402.1. Alternatively, where limiting conditions prevent compliance with Section R402.1, an approved design that minimizes deviation from Section R402.1 shall be provided for the following alterations:

 

1.         Roof replacements or a roof alteration that includes removing and replacing the roof covering where the roof assembly includes insulation entirely above the roof deck. Where limiting conditions require use of an approved design to minimize deviation from Section R402.1 for a Group R-2 building, a registered design professional or other approved source shall provide construction documents that identify the limiting conditions and the means to address them.

 

(Source:  Amended at 48 Ill. Reg. 14276, effective January 1, 2025)

 

Section 600.APPENDIX B   Illinois Commercial Stretch Energy Code Amendments to the 2024 International Energy Conservation Code Final Draft

 

The following Code sections shall be referenced in place of the corresponding 2024 IECC Final Draft sections.

 

CHAPTER 1 [CE] SCOPE AND ADMINISTRATION

 

User note:

 

About this chapter: Chapter 1 establishes the limits of applicability of the code and describes how the code is to be applied and enforced. Chapter 1 is in two parts: Part 1 − Scope and Application and Part 2 − Administration and Enforcement. Section C101, identifies what buildings, systems, appliances and equipment fall under its purview and references other I-Codes as applicable. Standards and codes are scoped to the extent referenced.

 

The code is intended to be adopted as a legally enforceable document and it cannot be effective without adequate provisions for its administration and enforcement. The provisions of Chapter 1 establish the authority and duties of the code official appointed by the authority having jurisdiction and also establish the rights and privileges of the design professional, contractor and property owner.

 

PART 1 − SCOPE AND APPLICATION

 

SECTION C101

SCOPE AND GENERAL REQUIREMENTS

 

C101.1 Title. This code shall be known as the 2023 Illinois Commercial Stretch Energy Code and shall mean:

 

With respect to the State facilities covered by 71 Ill. Adm. Code 600.Subpart B:

 

This Part, all additional requirements incorporated within Subpart B (including the 2024 International Energy Conservation Code Final Draft Commercial Provisions, including all published errata but excluding published supplements that encompass ASHRAE 90.1-2022), and any statutorily authorized adaptations to the incorporated standards adopted by CDB are effective 7/1/24.

 

With respect to the privately funded commercial facilities covered by 71 Ill. Adm. Code 600.Subpart C:

 

This Part, all additional requirements incorporated within Subpart C (including the 2024 International Energy Conservation Code Final Draft Commercial Provisions, including all published errata and excluding published supplements that encompass ASHRAE 90.1-2022), and any statutorily authorized adaptations to the incorporated standards adopted by CDB is effective upon adoption by a Municipality and takes the place of the Illinois Energy Conservation Code with respect to commercial buildings.

 

No unit of local government, including any home rule unit, may regulate energy efficient building standards for commercial buildings in a manner that is less stringent than the standards established pursuant to this Illinois Commercial Stretch Energy Code. 

 

C101.1.1 Adoption.  The Board shall adopt amendments to this Code and include site energy index standards as established in the Energy Efficient Building Act [20 ILCS 3125/55] as follows:

 

By June 30, 2024 with a site energy index no greater than .60 of the 2006 IECC;

By December 31, 2025 with a site energy index no greater than .50 of the 2006 IECC;

By December 31, 2028 with a site energy index no greater than .44 of the 2006 IECC;

By December 31, 2031 with a site energy index no greater than .39 of the 2006 IECC.

 

C101.2 Scope. This code applies to the design and construction of buildings not covered by the scope of the IECC – Residential Provisions.

 

C101.2.1 Appendices.  Provisions in the appendices shall not apply unless specifically adopted.

 

C101.3 Intent. The International Energy Conservation Code − Commercial Provisions provide market-driven, enforceable requirements for the design and construction of commercial buildings, providing minimum efficiency requirements for buildings that result in the maximum level of energy efficiency that is safe, technologically feasible, and life cycle cost effective, considering economic feasibility, including potential costs and savings for consumers and building owners, and return on investment. Additionally, the code provides jurisdictions with supplemental requirements, including ASHRAE 90.1, and optional requirements that lead to achievement of zero energy buildings, presently, and through glidepaths that achieve zero energy buildings by 2030 and on additional timelines sought by governments, and achievement of additional policy goals as identified by the Energy and Carbon Advisory Council and approved by the Board of Directors. Requirements contained in the code will include, but not be limited to, prescriptive- and performance-based pathways. The code may include non-mandatory appendices incorporating additional energy efficiency and greenhouse gas reduction resources developed by the Code Council and others. The code will aim to simplify code requirements to facilitate the code's use and compliance rate. The code is updated on a three-year cycle with each subsequent edition providing increased energy savings over the prior edition. This code is intended to provide flexibility to permit the use of innovative approaches and techniques to achieve this intent. This code is not intended to abridge safety, health or environmental requirements contained in other applicable codes or ordinances.

 

C101.4 Compliance. Commercial buildings shall meet the provisions of the Illinois Commercial Stretch Energy Code covered by 71 Ill. Adm. Code 600 Subpart C. The local authority having jurisdiction (AHJ) shall establish its own procedures for enforcement of the Illinois Commercial Stretch Energy Code.  Minimum compliance shall be demonstrated by submission of:

 

C101.4.1 Compliance materials. The code official shall be permitted to approve specific computer software, worksheets, compliance manuals and other similar materials that meet the intent of this code; or

 

C101.4.2 Professional seals.  The seal of the architect/engineer as required by Section 14 of the Illinois Architectural Practice Act [225 ILCS 305], Section 12 of the Structural Engineering Licensing Act [225 ILCS 340] and Section 14 of the Illinois Professional Engineering Practice Act [225 ILCS 325]; or

 

C101.4.3 COMcheck.^TM Compliance Certificates generated by the U.S. Department of Energy's COMcheck^TM Code compliance tool.

 

SECTION C102

APPLICABILITY

 

C102.1 Applicability. Where, in any specific case, different sections of this code specify different materials, methods of construction or other requirements, the most restrictive shall govern. Where there is a conflict between a general requirement and a specific requirement, the specific requirement shall govern.

 

C102.1.1 Mixed residential and commercial buildings. Where a building includes both residential building and commercial building portions, each portion shall be separately considered and meet the applicable provisions of Illinois Commercial Stretch Energy Code or the Illinois Residential Stretch Energy Code.

 

C102.2 Other laws. The provisions of this code shall not be deemed to nullify any provisions of local, state or federal law.

 

C102.3 Applications of references. References to chapter or section numbers, or to provisions not specifically identified by number, shall be construed to refer to such chapter, section or provision of this code.

 

C102.4 Referenced codes and standards. The codes and standards referenced in this code shall be those listed in Chapter 6, and such codes and standards shall be considered as part of the requirements of this code to the prescribed extent of each such reference and as further regulated in Sections C102.4.1 and C102.4.2.

 

C102.4.1 Conflicts. Where conflicts occur between provisions of this code and referenced codes and standards, the provisions of this code shall apply.

 

C102.4.2 Provisions in referenced codes and standards. Where the extent of the reference to a referenced code or standard includes subject matter that is within the scope of this code, the provisions of this code, as applicable, shall take precedence over the provisions in the referenced code or standard.

 

C102.5 Partial invalidity. If a portion of this code is held to be illegal or void, such a decision shall not affect the validity of the remainder of this code.

 

PART 2 − ADMINISTRATION AND ENFORCEMENT

SECTION C103

ALTERNATIVE MATERIALS, DESIGN AND METHODS OF

CONSTRUCTION AND EQUIPMENT

 

C103.1 General. The provisions of this code are not intended to prevent the installation of any material or to prohibit any design or method of construction not specifically prescribed by this code, provided that any such alternative has been approved. The code official shall have the authority to approve an alternative material, design or method of construction upon the written application of the owner or the owner's authorized agent. The code official shall first find that the proposed design is satisfactory and complies with the intent of the provisions of this code, and that the material, method or work offered is, for the purpose intended, not less than the equivalent of that prescribed in this code in quality, strength, effectiveness, fire resistance, durability, energy conservation and safety. The code official shall respond to the applicant, in writing, stating the reasons why the alternative was approved or was not approved.

 

C103.1.1 Above code programs. Buildings certified in compliance with Passive House Institute (PHI) or Passive House Institute U.S. (PHIUS) programs, or buildings that comply with Appendix CC, shall be deemed to meet the requirements of this code where such buildings also meet the requirements identified in Table C407.2(1).

 

SECTION C104

CODE COMPLIANCE AGENCY

 

C104.1 Creation of enforcement agency. The [INSERT NAME OF DEPARTMENT] is hereby created and the official in charge thereof shall be known as the authority having jurisdiction (AHJ). The function of the agency shall be the implementation, administration and enforcement of the provisions of this code.

 

C104.2 Appointment. The authority having jurisdiction (AHJ) shall be appointed by the chief appointing authority of the jurisdiction.

 

C104.3 Deputies. In accordance with the prescribed procedures of this jurisdiction and with the concurrence of the appointing authority, the authority having jurisdiction (AHJ) shall have the authority to appoint a deputy authority having jurisdiction (AHJ), other related technical officers, inspectors and other employees. Such employees shall have powers as delegated by the authority having jurisdiction (AHJ).

 

SECTION C105

CONSTRUCTION DOCUMENTS

 

C105.2.2 Electrification system. The construction documents shall provide details for additional electric infrastructure, including branch circuits, conduit, pre-wiring, panel capacity, and electrical service capacity, as well as interior and exterior spaces designated for future electric equipment, in compliance with the provisions of this code.

 

SECTION C107

INSPECTIONS

 

C107.2.5 Electrical system. Inspection shall verify lighting system controls, components, meters, and electric infrastructure as required by the code, approved plans and specifications. Where an electrical energy storage system area is required, inspections shall verify space availability and pathways to electrical service.

 

SECTION C202

GENERAL DEFINITIONS

 

2024 INTERNATIONAL ENERGY CONSERVATION CODE FINAL DRAFT.  The draft version of the 2024 IECC which includes changes from Public Comment Draft #2 and approved proposals from the Committee Action Report.

 

COMMERCIAL COOKING APPLIANCE. Appliances used in a commercial food service establishment for heating or cooking food. For the purpose of this definition, a commercial food service establishment is where food is regularly prepared for sale or is prepared on a scale that is by volume and frequency not representative of domestic household cooking.

 

ELECTRIC VEHICLE CAPABLE SPACE (EV CAPABLE SPACE). An automobile parking space provided with electrical infrastructure including raceway or cable assemblies, electrical capacity, and electrical distribution equipment space, necessary for connection to an EVSE.

 

REPLACEMENT COST. The cost to construct or replace an entire building with equal quality, construction type, and square footage, at current construction market labor and material rates.

 

SUBSTANTIAL IMPROVEMENT. Any repair, reconstruction, rehabilitation, alteration, addition or other improvement of a building or structure, the cost of which equals or is more than 50% of the market value replacement cost of the structure before the improvement or repair is started. Where the structure has sustained substantial damage, as defined in the International Building Code, any repairs are considered substantial improvement regardless of the actual repair work performed. Substantial improvement does not include the following:

 

1.         Improvement of a building ordered by the code official to correct health, sanitary or safety code violations and that are the minimum necessary to assure safe living conditions.

2.         Alteration of a historic building where the alteration will not affect the designation as a historic structure.

 

SECTION C401

GENERAL

 

C401.2 Application. Commercial buildings shall comply with Section C401.2.1 or C401.2.2.

 

C401.2.1 Commercial buildings shall comply with one of the following:

 

1.         Prescriptive Compliance. The Prescriptive Compliance option requires compliance with Sections C402 through C406 and Section C408. Dwelling units and sleeping units in Group R-2 buildings shall be deemed to be in compliance with this chapter, provided that they comply with Section R406.

2.         Simulated Building Performance. The Simulated Building Performance option requires compliance with Section C407.

 

Exception: Additions, alterations, repairs and changes of occupancy to existing buildings complying with Chapter 5.

 

C401.2.2 ASHRAE 90.1. Commercial buildings shall comply with the requirements of ANSI/ASHRAE/IES 90.1, Appendix CI, and the requirements of the sections indicated within Table C401.2.2.

 

TABLE C401.2.2 REQUIREMENTS FOR ASHRAE 90.1 COMPLIANCE

 

SECTIONa	TITLE
New Construction
C405.4	Horticultural lighting
C405.14	Electric Vehicle Power Transfer Infrastructure
C405.16	Electrical energy storage system
C405.18	Electric infrastructure
Additions and Alterations
C502.3.7	Additional energy efficiency credits
C503.3.4	Mechanical system acceptance testing
C503.3.5	Duct testing
C503.3.6	Controls
C503.3.7	System sizing
C503.6	Additional energy efficiency credits
C505.1.3	Additional energy efficiency for changes of occupancy

^a           Reference to a code section includes all the relative subsections as indicated in the table.

 

SECTION C402

BUILDING THERMAL ENVELOPE REQUIREMENTS

 

C402.5.1.3 Fenestration orientation.

The vertical fenestration shall comply with either equation (a) or (b):

 

a.         AW ≤ (AT)/4 and AE ≤ (AT)/4

b.         AW × SHGCW ≤ (AT × SHGCC)/5 and AE × SHGCE ≤ (AT × SHGCC)/5

 

Where:

 

AW	=	West-oriented vertical fenestration area (oriented within 45 degrees of true west to the south and within 22.5 degrees of true west to the north in the Northern Hemisphere)
AE	=	East-oriented vertical fenestration area (oriented within 45 degrees of true east to the south and within 22.5 degrees of true east to the north in the Northern Hemisphere)
AT	=	Total vertical fenestration area
SHGCC	=	SHGC criteria in Table C402.5
SHGCE	=	SHGC for east-oriented fenestration
SHGCW	=	SHGC for west-oriented fenestration

 

Exceptions:

 

1.         Buildings with shade on 75% of the east-oriented and west-oriented vertical fenestration areas from permanent projections, existing buildings, existing permanent infrastructure, or topography at 9 a.m. and 3 p.m., respectively, on the summer solstice (June 21).

2.         Alterations and additions with no increase in vertical fenestration area.

3.         Buildings where the east-oriented and west-oriented vertical fenestration area does not exceed 20% of the gross wall area for each of those façades, and SHGC on those facades is no greater than 90% of the criteria in Table C402.5.

 

SECTION C405

ELECTRICAL POWER AND LIGHTING SYSTEMS

 

C405.4 Horticultural lighting. Permanently installed luminaires shall have a photosynthetic photon efficacy of not less than 1.7 μmol/J for horticultural lighting in greenhouses and not less than 2.2 μmol/J for all other horticultural lighting. Luminaires for horticultural lighting in greenhouses shall be controlled by a device that automatically turns off the luminaire when sufficient daylight is available. Luminaires for horticultural lighting shall be controlled by a device that automatically turns off the luminaire at specific programmed times.

Exception: Cannabis facilities subject to 410 ILCS 705/10-45 − the Cannabis Regulation and Tax Act.

 

C405.14.2 EV Capable spaces. Each EV capable space used to meet the requirements of Section C405.14.1 shall comply with the following:

 

1.         A continuous raceway or cable assembly shall be installed between an enclosure or outlet located within 3 feet (914 mm) of the EV capable space and electrical distribution equipment.

2.         Installed raceway or cable assembly shall be sized and rated to supply a minimum circuit capacity in accordance with C405.14.5.

3.         The electrical distribution equipment to which the raceway or cable assembly connects shall have dedicated overcurrent protection device space and electrical capacity to supply a calculated load in accordance with Section C405.14.5.

4.         The enclosure or outlet and the electrical distribution equipment directory shall be marked: "For electric vehicle supply equipment (EVSE)."

 

C405.14.6 EVSE installation. EVSE shall be installed in accordance with NFPA 70 and shall be listed and labeled in accordance with UL 2202 or UL 2594. EVSE shall be accessible in accordance with the 2024 edition of the International Building Code Section 1107.

 

C405.16 Electrical energy storage system. Buildings shall comply with Section C405.16.1 or Section C405.16.2. Buildings shall comply with Section C405.16.3.

 

C405.16.1 Electrical energy storage system (ESS) capacity. Each building shall have one or more ESS with a total rated energy capacity and rated power capacity as follows:

 

1.         ESS rated energy capacity (kWh)≥1.0 x Installed On-site Renewable Electric Energy System Rated Power (kWDC)

2.         ESS rated power capacity (kW)≥0.25 x Installed On-Site Renewable Electric Energy System Rated Power (kWDC).

 

Where installed, DC coupled battery systems shall meet the requirements for rated energy capacity alone.

 

C405.16.2 Electrical energy storage system ready. Each building shall have one or more reserved ESS-ready areas to accommodate future electrical storage.

 

C405.16.3 Electrical energy storage installed or ready area. Areas where ESS is installed and ESS-ready areas shall comply with Sections C405.16.3.1 through C405.16.3.4.

 

C405.16.3.1 ESS installed or ready location. Each ESS installed or ready area shall be located in accordance with either Section 1207 of the 2024 International Fire Code or NFPA 855. For the purposes of locating and designing means of egress, ESS-installed or ready areas shall comply with either i) means of egress requirements for H-Occupancies of the 2024 International Fire Code or ii) Sections 7.2.1.4.2(3) and 7.11 of NFPA 101 (2015).

 

C405.16.3.2 ESS installed or ready minimum area requirements. Each ESS installed or ready area shall be sized in accordance with the spacing requirements of (i) either Section 1207 of the 2024 edition of the International Fire Code or NFPA 855 and (ii) the UL9540 or UL9540A designated rating of the planned system. Where rated to UL9540A, the area shall be sized in accordance with the manufacturer's instructions.

 

C405.16.3.3 Electrical distribution equipment. The onsite electrical distribution equipment shall have sufficient capacity, rating, and space to allow installation of overcurrent devices and circuit wiring in accordance with NFPA 70 for actual or future electrical ESS installation complying with the capacity criteria of Section C405.16. 3.4.

 

C405.16.3.4 ESS installed or ready minimum system capacity. Compliance with ESS-ready requirements in Sections C405.16.3.1 through C405.16.3.3 shall be based on a minimum total energy capacity and minimum rated power capacity as follows:

 

1.         ESS rated energy capacity (kWh) ≥ gross conditioned floor area of the three largest floors (ft2) x 0.0008 kWh/ft2

2.         ESS rated power capacity (kWh) ≥ gross conditioned floor area of the three largest floors (ft2) x 0.0002 kWh/ft²

 

C405.18 Electric infrastructure. New group R-2 occupancies that use fossil fuels for space heating, service water heating, cooking, or clothes drying shall install electric infrastructure in accordance with C405.18.1 through C405.18.5 and Section C105.2.2.

 

C405.18.1 Space heating. Locations with piping for fossil fuel warm-air furnaces and fossil fuel boilers shall comply with Section C405.18.1.1 or C405.18.1.2, as applicable.

 

Exception to C405.18.1: Where a branch circuit exists for space cooling equipment with the capacity to serve heat pump space heating equipment sized in accordance with the requirements of Section C403.1.1.

 

C405.18.1.1 Low-capacity space heating. Locations of fossil fuel warm-air furnaces with capacity less than 225,000 Btu/hr (65.9kW) and boilers with a capacity less than 300,000 Btu/hr (88kW) shall be provided with an individual branch circuit in accordance with all of the following:

 

1.         The branch circuit conductors shall terminate within 6 ft (2 m) of the location of the space heating equipment and shall be in a location with ready access.

2.         The branch circuit shall be sized to serve heat pump space heating equipment sized in accordance with the requirements of Section C403.1.1, and

3.         The branch circuit overcurrent device and the termination of the branch circuit shall be labeled "For future heat pump space heating equipment".

 

C405.18.1.2 Other space heating equipment. Locations of fossil fuel space heating equipment not covered under C405.18.1.1 shall be provided with a raceway in accordance with all of the following:

 

1.         The raceway shall be continuous from a branch circuit panel to a junction box located within the same space as the equipment or, where the equipment is located on the exterior of the building, within 3 ft (1m) of the equipment.

2.         The junction box, raceway, bus bar in the electric panel and conductors serving the electrical panel shall be sized to serve electric space heating equipment sized to serve the same load as the fossil fuel space heating equipment.

3.         The electrical panel shall have sufficient reserved physical space for branch circuit overprotection devices sized to serve electric equipment sized to serve the same load as the fossil fuel space heating appliance,

4.         The point of origin and the termination of the raceway shall be labeled “For future heat pump space heating equipment.”

 

C405.18.2 Water heating. Locations with piping for fossil fuel water heaters shall comply with Section C405.18.2.1 or C405.18.2.2, as applicable.

 

C405.18.2.1 Low-capacity water heating. Locations of fossil fuel water heaters with an input rating of less than 300,000 Btu/hr (88kW) shall comply with all of the following:

 

1.         An individual 30 ampere, 208/240-volt branch circuit shall be provided and terminate within 6 ft (2 m) of the water heater and shall be in a location with ready access.

2.         The branch circuit overcurrent protection device and the termination of the branch circuit shall be labeled "For future electric water heater".

3.         The space for containing the future water heater shall have a height of not less than 7 ft (2 m), a width of not less than 3 ft (1 m), a depth of not less than 3ft (1 m) and with a volume of not less than 700 ft3 (20 m3).

 

Exception to C405.18.2.1: Where the space containing the water heater provides for air circulation sufficient for the operation of a heat pump water heater, the minimum room volume shall not be required.

 

C405.18.2.2 Other water heating. Locations of fossil fuel water heating equipment not covered by Section C405.18.2.1 shall be provided with a raceway in accordance with all of the following:

 

1.         The raceway shall be continuous from an electric panel to a junction box located within the same space as the equipment or, where the equipment is located on the exterior of the building, within 3 ft (1m) of the equipment.

2.         The junction box, raceway, and bus bar in the electric panel and conductors serving the electric panel shall be sized to accommodate electric water heating equipment sized to serve the same load as the fossil fuel water heating equipment.

3.         The electric panel shall have sufficient reserved physical space for branch circuit overprotection devices sized to serve electric water heating equipment sized to serve the same load as the fossil fuel water heating equipment.

4.         The point of origin and termination of the raceway shall be labeled "For future electric water heating appliance."

 

C405.18.3 Non-commercial cooking. Locations of fossil fuel ranges, cooktops and ovens that are not commercial cooking appliances shall be provided with a dedicated individual branch circuit in accordance with all of the following:

 

1.         The branch circuit shall be rated for 208/240-volts and not less than 50 amps.

2.         The branch circuit shall terminate within 3 ft (1 m) of the appliance and shall be in a location with ready access.

3.         The point of origin and termination of the branch circuit shall be labeled "For future electric cooking appliance."

 

C405.18.4 Clothes drying. Locations with piping for fossil fuel clothes drying equipment shall comply with C405.18.4.1 or C405.18.4.2, as applicable.

 

C405.18.4.1 Residential drying. Locations of fossil fuel clothes drying appliances serving individual dwellings units shall be provided with a dedicated individual branch circuit in accordance with all of the following:

 

1.         The branch circuit shall be rated for 208/240-volts and not less than 30 amps.

2.         The branch circuit shall terminate within 3 ft (1 m) of the appliance and shall be in a location with ready access.

3.         The point of origin and termination of the branch circuit shall be labeled "For future electric clothes drying appliance."

 

C405.18.4.2 Non-residential drying. Locations of fossil fuel clothes drying appliances not covered by Section C405.18.4.1 shall be provided with a raceway in accordance with all of the following:

 

1.         The raceway shall be continuous from an electric panel to a junction box located within the same space as the appliance.

2.         The junction box, raceway, electric panel bus bar and conductors serving the electric panel shall be sized to serve electric clothes drying appliances having the same drying capacity as the fossil fuel appliance.

3.         The electric panel shall have sufficient reserved physical space for branch circuit overprotection devices sized to serve electric clothes drying appliances sized to serve the same load as the fossil fuel clothes drying appliances.

4.         The point of origin and termination of the raceway shall be labeled "For future electric clothes drying appliance".

 

C405.18.5 Onsite transformers. Enclosed spaces and underground vaults containing onsite electric transformers on the building side of the electric utility meter shall have sufficient space to accommodate transformers sized to serve the additional electric loads identified in C405.18.1, C405.18.2, C405.18.3 and C405.18.4.

 

SECTION C406

ADDITIONAL EFFICIENCY, RENEWABLE, AND LOAD

MANAGEMENT REQUIREMENTS

 

C406.1.1 Additional energy efficiency credit requirements. Buildings shall comply with measures from C406.2 to achieve not less than the number of required efficiency credits from Table C406.1.1(1) based on building occupancy group and climate zone including any energy credit adjustments in accordance with C406.1.1.1.  Where a project contains multiple occupancies, the total required energy credits from each building occupancy shall be weighted by the gross conditioned floor area to determine the weighted average project energy credits required. Accessory occupancies shall be included with the primary occupancy group for purposes of Section C406.

 

Exception:

 

1.         Portions of buildings devoted to manufacturing or industrial use.

 

SECTION C407

SIMULATED BUILDING PERFORMANCE

 

C407.2 Mandatory requirements. Compliance based on total building performance requires that a proposed design meet all of the following:

 

1.         The requirements of the sections indicated within Table C407.2(1).

2.         A site energy use that is less than or equal to the percent of the site energy use (SEUC) of the standard reference design calculated in Equation 4-32. The reduction in site energy use of the proposed design associated with on-site and off-site renewable energy shall not be included in the total site energy use.

 

PSEUC	=	100 x (0.80 +0.25- ECr/1000) (Equation 4-32)
PSEUC	=	Percentage of site energy use applied to standard reference design
ECr	=	Energy efficiency credits required for the building in accordance with Section C406.1 (do not include load management and renewable credits)

 

Modify Table C407.2(1) as follows:

 

TABLE C407.2(1)

REQUIREMENTS FOR SIMULATED BUILDING PERFORMANCE

 

SECTIONa	TITLE
Envelope
C402.5.1.3	Fenestration Orientation

a.         Reference to a code section includes all the relative subsections except as indicated in the table.

 

Modify Table C407.4.1(1) as follows:

 

TABLE C407.4.1(1)

SPECIFICATIONS FOR THE STANDARD REFERENCE AND PROPOSED DESIGNS

 

Vertical fenestration other than opaque doors	Area 1. The proposed vertical fenestration area; where the proposed vertical fenestration area is less than 40% of the above-grade wall area. 2. 40% of above grade wall area; where the proposed vertical fenestration area is 40% or more of the above grade wall area 3. Fenestration orientation shall comply with Section C402.5.1.3	As proposed
	U-factor: as specified in Table C402.5	As proposed
	1. SHGC: as specified in Table C402.5 except that for climates with no requirement (NR) SHGC = 0.40 shall be used. 2. Fenestration SHGC shall comply with Section C402.5.1.3	As proposed
	External shading and PF: none	As proposed

 

SECTION C503

ALTERATIONS

 

C503.6 Additional credit requirements for alterations. Alterations that are substantial improvements shall comply with measures from Sections C402.5 and C405.18 and meet a site EUI by building type in accordance with ASHRAE Standard 100 Table 7-2a. Replacement cost shall be determined by a registered design professional or approved agency and approved by the code official. Where a project contains multiple occupancies, site EUI requirements shall be weighted by the gross conditioned floor area to determine the weighted average site EUI required. Accessory occupancies, other than Groups F or H, shall be included with the primary occupancy group for the purposes of this section.

 

Exceptions:

 

1.         Alterations that do not contain conditioned space.

2.         Portions of buildings devoted to manufacturing or industrial use.

3.         Alterations to buildings where the building after the alteration complies with Section C407.

4.         Alterations that are permitted with an addition complying with Section C502.3.7.

5.         Group R occupancies that achieve an ERI score of 80 or below without on-site renewable energy included in accordance with RESNET/ICC 301, for each dwelling unit.

 

SECTION C505

CHANGE OF OCCUPANCY OR USE

 

C505.1.3 Additional energy efficiency for changes of occupancy. Where a space is converted from one occupancy type to another occupancy type, it shall comply with Section C406.1.1.1.

 

Exceptions:

 

1.         Alterations complying with Section C503.6.

2.         Where no less than 50% of the peak space heating and peak water heating load of the building is served by heat pump equipment.

 

Appendix CD

The 2030 Glide Path

 

Remove Section CD101.1 Prescriptive compliance and Table CD101.1 in their entirety.

 

Appendix CG

All-Electric Commercial Building Provisions

 

This appendix is removed and is not included in the Illinois Commercial Stretch Energy Code.

 

Appendix CI

Total Building Performance Pathway

 

CI101 Scope.  This section establishes criteria for buildings that demonstrate compliance using total building performance utilizing site energy in accordance with Section 4.2.1.1 of ANSI/ASHRAE/IESNA 90.1.

 

CI102 Compliance based on site energy.  Buildings shall comply with ANSI/ASHRAE/IESNA 90.1 as modified by this section. 

 

CI102.1 Terms.  For the purposes of compliance with this appendix, terminology in ANSI/ASHRAE/IESNA 90.1 shall be modified as follows:

 

1.         Replace references to energy cost with references to site energy in Sections G1.2.2, G1.3.2, G2.1, G2.5 and G2.4.2 section heading.

2.         Baseline building performance shall be defined as "the annual site energy cost for a building design intended for use as a baseline for rating above-standard design or when using the Performance Rating Method as an alternative path for minimum standard compliance in accordance with Section 4.2.1.1".

3.         Proposed building performance shall be defined as “the annual site energy calculated for a proposed design."

 

CI102.2 Section 4.2.1.1.  Section 4.2.1.1 shall be replaced with the following: 

 

New buildings shall comply with Section 4.2.2 through 4.2.5 and either the provisions of:

 

a.         Sections 5, "Building Envelope"; 6, "Heating, Ventilating, and Air Conditioning"; 7, "Service Water Heating"; 8, "Power"; 9, "Lighting"; 10, "Other Equipment"; and 11, "Additional Efficiency Requirements"; or

b.         Normative Appendix G, "Performance Rating Method".

 

When using Normative Appendix G, the Performance Index (Site Energy) of new buildings, additions to existing buildings, and/or alterations to existing buildings shall be less than or equal to the Performance Index Target (PI t) when calculated in accordance with the following:

 

PIt = [BBUE + (BPFsite × BBRE)- PRE] / BBP

 

Where:

 

PI	=	Performance Index (Site Energy) calculated in accordance with Section G1.2.
BBUE	=	Baseline building unregulated site energy, the portion of the annual site energy of a baseline building design that is due to unregulated energy use.
BBRE	=	baseline building regulated site energy, the portion of the annual site energy cost of a baseline building design that is due to regulated energy use.
BPF	=	building performance factor from Table 4.2.1.1. For building area types not listed in Table 4.2.1.1 use "All others." Where a building has multiple building area types, the required BPF shall be equal to the area-weighted average of the building area types based on their gross floor area. Where a project includes an existing building and an addition, the required BPF shall be equal to the area-weighted average, based on the gross floor area, of the existing building BPF determined as described in Section 4.2.1.3 and the addition BPF from Table 4.2.1.1.
BBP	=	Baseline building performance.
PBP	=	Proposed building performance, including the reduced, annual site energy associated with all on-site renewable energy generation systems.
PBPnre	=	Proposed building performance without any credit for reduced annual energy from on-site renewable energy generation systems.
PBPpre	=	Proposed building performance, excluding any renewable energy system in the proposed design and including an on-site renewable energy system that meets but does not exceed the requirements of Section 10.5.1.1 modeled following the requirements for a budget building design in Table 12.5.1.
PRE		PBPnre – PBPpre

 

When (PBPpre – PBP)/BBP > 0.05, new buildings, additions to existing buildings, and/or alterations to existing buildings shall comply with the following:

 

PCSEI + [(PBPnre – PBP)/BBP] – 0.05 < PCSEIt

 

When (PBPpre – PBP)/BBP > 0.05, new buildings, additions to existing buildings, and/or alterations to existing buildings shall comply with the following:

 

PCI + [(PBPpre – PBP)/BBP] – 0.05 < PCIt

 

Informative Notes:

 

1.         PBPnre = proposed building performance, no renewable energy

2.         PBPpre = proposed building performance, prescriptive renewable energy

3.         PRE = prescriptive renewable energy

 

CI102.3 Building performance factors.  Table 4.2.1.1 Building Performance Factor (BPF) shall be replaced with Table CI102.3.

 

Table CI102.3 Building Performance Factors (BPF), Site Energy

 

Building Area Type	Climate Zone
	4A	5A
Multifamily	0.61	0.56
Healthcare/hospital	0.62	0.65
Hotel/motel	0.65	0.63
Office	0.47	0.49
Restaurant	0.66	0.69
Retail	0.47	0.52
School	0.42	0.44
Warehouse	0.38	0.46
All others	0.55	0.57

 

CI102.4 Section G1.2.2.  Section G1.2.2 shall be replaced with the following: 

 

The performance of the proposed design is calculated in accordance with provisions of this appendix using the following formula:

 

Performance Site Energy Index

=

Proposed building performance/Baseline building performance

 

Both the proposed building performance and the baseline building performance shall include all end-use load components within and associated with the building when calculating the Performance Site Energy Index.

 

CI102.5 Section G1.3.2.  Item a. in Section G1.3.2 shall be replaced as follows, and item r. added as follows:

 

a.         The following documentation shall be submitted to the rating authority: The simulation program used, the version of the simulation program, and the results of the energy analysis including the calculated values for the baseline building unregulated site energy (BBUE), baseline building regulated site energy (BBRE), Building Performance Factor (BPF), baseline building performance, the proposed building performance, Performance Site Energy Index (PCSEI), and Performance Site Energy Index Target (PIt).

p.         For any exceptional calculation methods employed, document the predicted energy savings by energy type, the site energy savings, a narrative explaining the exceptional calculation method performed, and theoretical or empirical information supporting the accuracy of the method.

 

CI102.6 Section G2.4.2.  Section G2.4.2 shall be renamed "Annual Site Energy".  The informative note for sections G2.4.2 and G2.4.2.2 shall be removed.  The first sentence in section G2.4.2. shall be replaced with the following:

 

The baseline building performance and proposed building performance shall be determined using conversion factors in Table CI103.6

 

Table CI103.6 Units of Fuel to Site Energy Conversion Factors

 

Building Project Energy Source	Units	Site energy Btu/unit (W-h/unit)
Electricity	kWh	3,412
Natural Gas	Therm (GJ)	100,000 (277,778)
Propane	Therm (GJ)	100,000 (277,778)
Distillate fuel oil	Gallon (L)	137,600 (10,651)

 

CI102.7 Section G2.5.  Section G2.5, item e shall be replaced with the following:

 

e.         The Performance Site Energy Index calculated with and without the exceptional calculation method.

 

(Source:  Added at 48 Ill. Reg. 14276, effective January 1, 2025)

 

Section 600.APPENDIX C   Illinois Residential Stretch Energy Code Amendments to the 2021 International Energy Conservation Code

 

The following Code sections shall be referenced in place of the corresponding 2021 IECC sections.

 

PART 1 − SCOPE AND APPLICATION

 

SECTION R101

SCOPE AND GENERAL REQUIREMENTS

 

R101.1 Title. This code shall be known as the 2023 Illinois Residential Stretch Energy Code or "this Code" and shall mean:

 

With respect to the residential buildings covered by 71 Ill Adm Code 600 Subpart D:

 

This Part, all additional requirements incorporated within Subpart D (including the 2021 International Energy Conservation Code Residential Provisions, including all published errata but excluding published supplements) and any statutorily authorized adaptations to the incorporated standards adopted by CDB is effective upon adoption by a Municipality and takes the place of the Illinois Energy Conservation Code with respect to residential buildings.

 

No unit of local government, including any home rule unit, may regulate energy efficient building standards for residential buildings in a manner that is less stringent than the standards established pursuant to this Illinois Residential Stretch Energy Code. 

 

R101.1.1 Adoption.  The Board shall adopt amendments to this Code and include site energy index standards as established in the Energy Efficient Building Act [20 ILCS 3125/55] as follows:

 

By June 30, 2024 with a site energy index no greater than .50 of the 2006 IECC;

By December 31, 2025 with a site energy index no greater than .40 of the 2006 IECC;

By December 31, 2028 with a site energy index no greater than .33 of the 2006 IECC;

By December 31, 2031 with a site energy index no greater than .25 of the 2006 IECC.

 

R101.2 Scope. This code applies to residential buildings, building sites and associated systems and equipment.

 

R101.2.1 Appendices.  Provisions in the appendices shall not apply unless specifically adopted.

 

R101.3 Intent. This code shall regulate the design and construction of buildings for the effective use and conservation of energy over the useful life of each building. This code is intended to provide flexibility to permit the use of innovative approaches and techniques to achieve this objective. This code is not intended to abridge safety, health or environmental requirements contained in other applicable codes or ordinances.

 

R101.4 Applicability. Where, in any specific case, different sections of this code specify different materials, methods of construction or other requirements, the most restrictive shall govern. Where there is a conflict between a general requirement and a specific requirement, the specific requirement shall govern.

 

R101.4.1 Mixed residential and commercial buildings. Where a building includes both residential building and commercial building portions, each portion shall be separately considered and meet the applicable provisions of the Illinois Commercial Stretch Code or the Illinois Residential Stretch Code.

 

R101.5 Compliance. Residential buildings shall meet the provisions of the Illinois Residential Stretch Code covered by 71 Ill Adm. Code 600 Subpart D.  The local authority having jurisdiction (AHJ) shall establish its own procedures for enforcement of the Illinois Residential Stretch Code.  Minimum compliance shall be demonstrated by submission of:

 

R101.5.1 Compliance materials. The code official shall be permitted to approve specific computer software, worksheets, compliance manuals and other similar materials that meet the intent of this code; or

 

R101.5.2 Professional seals.  The seal of the architect/engineer as required by Section 14 of the Illinois Architectural Practice Act [225 ILCS 305], Section 12 of the Structural Engineering Licensing Act [225 ILCS 340] and Section 14 of the Illinois Professional Engineering Practice Act [225 ILCS 325]; or

 

R101.5.3 REScheck. ^TM Compliance Certificates generated by the U.S. Department of Energy's REScheck^TM Code compliance tool.

 

SECTION R102

ALTERNATIVE MATERIALS, DESIGN AND

METHODS OF CONSTRUCTION AND EQUIPMENT

 

R102.1 General. The provisions of this code are not intended to prevent the installation of any material or to prohibit any design or method of construction not specifically prescribed by this code, provided that any such alternative has been approved. The code official shall have the authority to approve an alternative material, design or method of construction upon the written application of the owner or the owner's authorized agent. The code official shall first find that the proposed design is satisfactory and complies with the intent of the provisions of this code, and that the material, method or work offered is, for the purpose intended, not less than the equivalent of that prescribed in this code for strength, effectiveness, fire resistance, durability, energy conservation and safety. The code official shall respond to the applicant, in writing, stating the reasons why the alternative was approved or was not approved.

 

R102.1.1 Above code programs. Buildings certified in compliance with the Passive House Institute (PHI) or Passive House Institute U.S. (PHIUS) Passive Building Standards programs or buildings that comply with Appendix RC shall be deemed to meet the requirements with this code where such buildings also meet the requirements identified in Table R405.2 and the building thermal envelope is greater than or equal to levels of efficiency and solar heat gain coefficients (SHGC) in Tables 402.1.2 and 402.1.3.

 

PART 2 − ADMINISTRATION AND ENFORCEMENT

 

SECTION R103

SCOPE AND ADMINISTRATION

 

R103.2 Information on construction documents. Construction documents shall be drawn to scale on suitable material. Electronic media documents are permitted to be submitted where approved by the code official. Construction documents shall be of sufficient clarity to indicate the location, nature and extent of the work proposed, and show in sufficient detail pertinent data and features of the building, systems and equipment as herein governed. Details shall include the following as applicable:

 

1.         Energy compliance path.

2.         Insulation materials and their R-values.

3.         Fenestration U-factors and solar heat gain coefficients (SHGC).

4.         Area-weighted U-factor and solar heat gain coefficients (SHGC) calculations.

5.         Mechanical system design criteria.

6.         Mechanical and service water-heating systems and equipment types, sizes and efficiencies.

7.         Equipment and system controls.

8.         Duct sealing, duct and pipe insulation and location.

9.         Air sealing details.

 

R103.2.1 Building thermal envelope depiction. The building thermal envelope shall be represented on the construction documents.

 

R103.2.2 Solar-ready system. Where a solar-ready zone is provided, the construction documents shall provide details for dedicated roof area, structural design for roof dead and live load, ground snow load, and routing of conduit or pre-wiring from solar-ready zone to electrical service panel or plumbing from solar-ready zone to service water heating system.

 

SECTION R105

INSPECTIONS

 

R105.1 General. Construction or work for which a permit is required shall be subject to inspection by the code official or his or her designated agent, and such construction or work shall remain visible and able to be accessed for inspection purposes until approved. It shall be the duty of the permit applicant to cause the work to remain visible and able to be accessed for inspection purposes. Neither the code official nor the jurisdiction shall be liable for expense entailed in the removal or replacement of any material, product, system or building component required to allow inspection to validate compliance with this code.

 

R105.2 Required inspections. The code official or his or her designated agent, upon notification, shall make the inspections set forth in Sections R105.2.1 through R105.2.5.

 

R105.2.1 Footing and foundation inspection. Inspections associated with footings and foundations shall verify compliance with the code as to R-value, location, thickness, depth of burial and protection of insulation as required by the code and approved plans and specifications.

 

R105.2.2 Framing and rough-in inspection. Inspections at framing and rough-in shall be made before application of interior finish and shall verify compliance with the code as to: types of insulation and corresponding R-values and their correct location and proper installation; fenestration properties such as U-factor and SHGC and proper installation; air leakage controls as required by the code; and approved plans and specifications.

 

R105.2.3 Plumbing rough-in inspection. Inspections at plumbing rough-in shall verify compliance as required by the code and approved plans and specifications as to types of insulation and corresponding R-values and protection, and required controls.  Where the solar-ready zone is installed for solar water heating, inspections shall verify pathways for routing of plumbing from solar-ready zone to service water heating system.

 

R105.2.4 Mechanical rough-in inspection. Inspections at mechanical rough-in shall verify compliance as required by the code and approved plans and specifications as to installed HVAC equipment type and size, required controls, system insulation and corresponding R- value, system air leakage control, programmable thermostats, dampers, whole-house ventilation, and minimum fan efficiency.

 

Exception: Systems serving multiple dwelling units shall be inspected in accordance with Section C105.2.4.

 

R105.2.5 Electrical rough-in inspection. Inspections at electrical rough-in shall verify compliance as required by the code and the approved plans and specifications as to the locations, distribution, and capacity of the electrical system. Where the solar-ready zone is installed for electricity generation, inspections shall verify conduit or pre-wiring from solar-ready zone to electrical panel.

 

R105.2.6 Final inspection. The building shall have a final inspection and shall not be occupied until approved. The final inspection shall include verification of the installation of all required building systems, equipment and controls and their proper operation and the required number of high-efficacy lamps and fixtures.

 

R105.3 Reinspection. A building shall be reinspected where determined necessary by the code official.

 

R105.4 Approved inspection agencies. The code official is authorized to accept reports of third-party inspection agencies not affiliated with the building design or construction,

 

SECTION R202

GENERAL DEFINITIONS

 

APPROVED SOURCE. An independent person, firm or corporation, approved by the building official, who is competent and experienced in the application of engineering principles to materials, methods or systems analyses.

 

AUTOMOBILE PARKING SPACE. A space within a building or private or public parking lot, exclusive of driveways, ramps, columns, office and work areas, for the parking of an automobile.

 

DEMAND RESPONSE SIGNAL.  A signal that indicates a price or a request to modify electricity consumption for a limited time period.

 

DEMAND RESPONSIVE CONTROL. A control capable of receiving and automatically responding to a demand response signal.

 

ELECTRIC VEHICLE (EV). An automotive-type vehicle for on-road use, such as passenger automobiles, buses, trucks, vans, neighborhood electric vehicles, and electric motorcycles, primarily powered by an electric motor that draws current from a building electrical service, EVSE, a rechargeable storage battery, a fuel cell, a photovoltaic array, or another source of electric current. 

 

ELECTRIC VEHICLE READY SPACE (EV READY SPACE). An automobile parking space that is provided with a branch circuit and either an outlet, junction box or receptacle, that will support an installed EVSE.

 

ELECTRIC VEHICLE SUPPLY EQUIPMENT (EVSE). Equipment for plug-in power transfer including the ungrounded, grounded and equipment grounding conductors, and the electric vehicle connectors, attached plugs, personal protection system and all other fittings, devices, power outlets or apparatus installed specifically for the purpose of transferring energy between the premises wiring and the electric vehicle.

 

GAS HEAT PUMP SPACE HEATING SYSTEM.  Gas heat pump space heating systems consist of an outdoor combustion unit and heat exchanger(s) inside the building.  The outdoor combustion unit is installed outside the building envelope and uses the heat of combustion to drive a refrigeration cycle that pumps heat into the building.  Annual fuel utilization efficiencies (AFUE) greater than 120% and 140% are achieved by pumping the heat of combustion and additional heat from the ambient air into the building.  The heat is then distributed indoors via forced air hydronic air handler(s), via floors and other radiant systems, or through combinations of forced air and radiant systems.

 

RESIDENTIAL BUILDING.  A detached one-family or two-family dwelling or any building that is three stories or less in height above grade that contains multiple dwelling units, in which the occupants reside on a primarily permanent basis, such as a townhouse, a row house, an apartment house, a convent, a monastery, a rectory, a fraternity or sorority house, a dormitory, and a rooming house; provided, however, that when applied to a building located within the boundaries of a municipality having a population of 1,000,000 or more, the term "RESIDENTIAL BUILDING" means a building containing one or more dwelling units, not exceeding four (4) stories above grade, where occupants are primarily permanent.

 

SOLAR-READY ZONE. A section or sections of the roof or building overhang designated and reserved for the future installation of a solar photovoltaic or solar thermal system.

 

SECTION R401

GENERAL

 

R401.1 Scope. This chapter applies to residential buildings.

 

R401.2 Application. Residential buildings shall comply with either Sections R401.2.1, R401.2.2, or R401.2.3.

 

Exception: Additions, alterations, repairs and changes of occupancy to existing buildings complying with Chapter 5.

 

R401.2.1 Prescriptive Compliance Option. The Prescriptive Compliance Option requires compliance with Sections R401 through R404 and R408.

 

R401.2.2 Total Building Performance Option. The Total Building Performance Option requires compliance with Section R405.

 

R401.2.3 Energy Rating Index Option. The Energy Rating Index (ERI) Option requires compliance with Section R406.

 

R401.2.4 Tropical Climate Region Option. The Tropical Climate Region Option requires compliance with Section R407.

 

R401.3 Certificate. A permanent certificate shall be completed by the builder or other approved party and posted on a wall in the space where the furnace is located, a utility room or an approved location inside the building. Where located on an electrical panel, the certificate shall not cover or obstruct the visibility of the circuit directory label, service disconnect label or other required labels. The certificate shall indicate the following:

 

1.         The predominant R-values of insulation installed in or on ceilings, roofs, walls, foundation components such as slabs, basement walls, crawl space walls and floors and ducts outside conditioned spaces.

2.         U-factors of fenestration and the solar heat gain coefficient (SHGC) of fenestration. Where there is more than one value for any component of the building envelope, the certificate shall indicate both the value covering the largest area and the area weighted average value if available.

3.         The results from any required duct system and building envelope air leakage testing performed on the building.

4.         The types, sizes and efficiencies of heating, cooling and service water-heating equipment. Where a gasfired unvented room heater, electric furnace or baseboard electric heater is installed in the residence, the certificate shall indicate "gas-fired unvented room heater", "electric furnace" or "baseboard electric heater", as appropriate. An efficiency shall not be indicated for gas-fired unvented room heaters, electric furnaces and electric baseboard heaters.

5.         Where on-site photovoltaic panel systems have been installed, the array capacity, inverter efficiency, panel tilt and orientation shall be noted on the certificate.

6.         For buildings where an Energy Rating Index score is determined in accordance with Section R406, the Energy Rating Index score, both with and without any on-site generation, shall be listed on the certificate.

7.         The code edition under which the structure was permitted, and the compliance path used and where applicable, the additional efficiency measures selected for compliance with R408.

 

SECTION R403

SYSTEMS

 

R403.1 Controls. Not less than one thermostat shall be provided for each separate heating and cooling system. The primary heating or cooling system serving the dwelling unit shall comply with Sections R403.1.1, R403.1.2, and R403.1.3.

 

R403.1.1 Programmable thermostat. The thermostat controlling the primary heating or cooling system of the dwelling unit shall be capable of controlling the heating and cooling system on a daily schedule to maintain different temperature set points at different times of day and different days of the week. This thermostat shall include the capability to set back or temporarily operate the system to maintain zone temperatures of not less than 55°F (13°C) to not greater than 85°F (29°C). The thermostat shall be programmed initially by the manufacturer with a heating temperature setpoint of not greater than 70°F (21°C) and a cooling temperature setpoint of not less than 78°F (26°C).

 

R403.1.2 Heat pump supplementary heat. Heat pumps having supplementary electric-resistance heat shall have controls that, except during defrost, prevent supplemental heat operation when the heat pump compressor can meet the heating load.

 

R403.1.3 Demand responsive thermostat. The thermostat shall be provided with a demand responsive control capable of communicating with the Virtual End Node (VEN) using a wired or wireless bi-directional communication pathway that provides the homeowner the ability to voluntarily participate in utility demand response programs, where available. The thermostat shall be capable of executing the following actions in response to a demand response signal:

 

1.         Automatically increasing the zone operating cooling set point by the following values: 1°F (0.5°C), 2°F (1°C), 3°F (1.5°C), and 4°F (2°C).

2.         Automatically decreasing the zone operating heating set point by the following values: 1°F (0.5°C), 2°F (1°C), 3°F (1.5°C), and 4°F (2°C).

 

Thermostats controlling single stage HVAC systems shall comply with Section R403.1.2.1. Thermostats controlling variable capacity systems shall comply with Section R403.1.2.2. Thermostats controlling multi-stage HVAC systems shall comply with either Section R403.1.2.1 or R403.1.2.2. Where a demand response signal is not available the thermostat shall be capable of performing all other functions.

 

Exception: Assisted living facilities.

 

R403.1.3.1 Single stage HVAC system controls. Thermostats controlling single stage HVAC systems shall be provided with a demand responsive control that complies with one of the following:

 

1.         Certified OpenADR 2.0a VEN, as specified under Clause 11, Conformance.

2.         Certified OpenADR 2.0b VEN, as specified under Clause 11, Conformance.

3.         Certified by the manufacturer as being capable of responding to a demand response signal from a certified OpenADR 2.0b VEN by automatically implementing the control functions requested by the VEN for the equipment it controls.

4.         IEC 62746-10-1.

5.         The communication protocol required by a controlling entity, such as a utility or service provider, to participate in an automated demand response program.

6.         The physical configuration and communication protocol of CTA 2045-A or CTA-2045-B.

 

R403.1.3.2 Variable capacity and two stage HVAC system controls. Thermostats controlling variable capacity and two stage HVAC system shall be provided with a demand responsive control that complies with the communication and performance requirements of AHRI 1380.

 

R403.5.4 Demand responsive water heating. Electric storage water heaters with a rated water storage volume of 40 gallons (150L) to 120 gallons (450L) and a nameplate input rating equal to or less than 12kW shall be provided with demand responsive controls in accordance with Table R403.5.4 or another equivalent approved standard.

 

Exceptions:

 

1.         Water heaters that are capable of delivering water at a temperature of 180°F (82°C) or greater.

2.         Water heaters that comply with Section IV, Part HLW or Section X of the ASME Boiler and Pressure Vessel Code.

3.         Water heaters that use 3-phase electric power

 

TABLE R403.5.4

DEMAND RESPONSIVE CONTROLS FOR WATER HEATING

 

Equipment Type	Controls
	Manufactured Before 7/1/2025	Manufactured On or After 7/1/2025
Electric storage water heaters	AHRI Standard 1430-2022 (I-P) or ANSI/CTA-2045-B Level 1 and also capable of initiating water heating to meet the temperature set point in response to a demand response signal.	AHRI Standard 1430-2022 (I-P)

 

SECTION R404

ELECTRICAL POWER AND LIGHTING SYSTEMS

 

R404.4 Electric vehicle power transfer infrastructure. New automobile parking spaces for one- and two-family dwellings and townhouses shall be provided in accordance with this section.  All other new residential parking facilities shall be provided with electric vehicle power transfer infrastructure in accordance with Section C405.14 of the Illinois Commercial Stretch Energy Code. 

 

R404.4.1 Quantity.  Each dwelling unit with a designated attached or detached garage or other onsite private parking provided adjacent to the dwelling unit shall be provided with one EV ready space.

 

R404.4.2 EV ready spaces.  Each branch circuit serving EV ready spaces used to comply with Section R404.4 shall comply with all of the following:

 

1.         Terminate at an outlet or enclosure located within 3 feet (914 mm) of each EV ready space it serves.

2.         Be sized for a minimum EV charging load of 7.2 kVA.

3.         The panelboard or other electrical distribution equipment directory shall designate the branch circuit as "For electric vehicle supply equipment (EVSE)" and the outlet or enclosure shall be marked "For electric vehicle supply equipment (EVSE)".

4.         Where a circuit is shared or managed, it shall be in accordance with NFPA 70.

 

R404.5 Electric readiness. Systems using fossil fuel: water heaters, household clothes dryers, conventional cooking tops, conventional ovens and space heating equipment shall comply with the requirements of Sections R404.5.1 through R404.5.5

 

R404.5.1 Cooking products. An individual branch circuit outlet with a rating not less than 240-volts, 40-amperes shall be installed, and terminate within three feet of conventional cooking tops, conventional ovens or cooking products combining both.

 

Exception: Cooking products not installed in an individual dwelling unit.

 

R404.5.2 Household clothes dryers.  An individual branch circuit outlet with a rating not less than 240-volts, 30-amperes shall be installed, and terminate within three feet (304 mm) of each household clothes dryer.

 

Exception: Clothes dryers that serve more than one dwelling unit and are located outside of a dwelling unit.

 

R404.5.3 Water heaters. Locations of fossil fuel water heaters shall comply with all of the following:

 

1.         An individual branch circuit outlet with a rating not less than either 240-volts, 30-amperes shall be installed, and terminate within three feet (304 mm) of each fossil fuel water heater.

2.         The space for containing the future water heater shall have a height of not less than 7 ft (2 m), a width of not less than 3 ft (1 m), a depth of not less than 3ft (1 m) and with a volume of not less than 700 ft3 (20 m3).

 

Exceptions:

 

1.         Water heaters in a centralized water heating system serving multiple dwelling units in an R-2 occupancy which comply with Section C405.17.

2.         Where the space containing the water heater provides for air circulation sufficient for the operation of a heat pump water heater, the minimum room volume shall not be required.

 

R404.5.4 Combustion space heating. A designated exterior location(s) in accordance with the following:

 

1.         Natural drainage for condensate from cooling equipment heat pump operation or a condensate drain located within 3 feet (914 mm), and

2.         A dedicated branch circuit in compliance with IRC Section E3702.11 based on heat pump space heating equipment sized in accordance with R403.7 and terminating within 3 feet (914 mm) of the location with no obstructions. Both ends of the branch circuit shall be labeled "For Future Heat Pump Space Heater."

 

R404.5.5 Electrification-ready circuits. The unused conductors required by Sections R404.5.1 through R404.5.4 shall be labeled with the word "spare." Space shall be reserved in the electrical panel in which the branch circuit originates for the installation of an overcurrent device. Capacity for the circuits required by Sections R404.5.1 through R404.5.4 shall be included in the load calculations of the original installation.

 

R404.6 Renewable energy infrastructure. The building shall comply with the requirements of R404.6.1 or R404.6.2.

 

R404.6.1 One- and two- family dwellings and townhouses. One- and two-family dwellings and townhouses shall comply with Sections R404.6.1.1 through R404.6.1.4.

 

Exceptions:

 

1.         A dwelling unit with a permanently installed on-site renewable energy system.

2.         A dwelling unit with a solar-ready zone area that is less than 500 square feet (46 m2) of roof area oriented between 110 degrees and 270 degrees of true north.

3.         A dwelling unit with less than 500 square feet (46m2) of roof area oriented between 110 degrees and 270 degrees of true north.

4.         Dwelling units where 50% of the solar-ready area is shaded from direct-beam sunlight by natural objects or by structures that are not part of the building for more than 2500 annual hours between 8:00 a.m. and 4:00 p.m.

 

R404.6.1.1 Solar-ready zone area. The total area of the solar-ready zone shall not be less than 250 square feet (23.2 m2) and shall be composed of areas not less than 5.5 feet (1676 mm) in one direction and not less than 80 square feet (7.4 m2) exclusive of access or set back areas as required by the International Residential Code.

 

Exception: Dwelling units in townhouses three stories or less in height above grade plane and with a total floor area less than or equal to 2,000 square feet (186 m2) per dwelling shall be permitted to have a solar-ready zone area of not less than 150 square feet (14 m2).

 

R404.6.1.2 Obstructions. Solar-ready zones shall be free from obstructions, including but not limited to vents, chimneys, and roof-mounted equipment.

 

R404.6.1.3 Electrical service reserved space. The main electrical service panel shall have a reserved space for a dual pole circuit breaker and shall be labeled “For Future Solar Electric.” The reserved space shall be at the opposite (load) end of the busbar from the primary energy source.

 

R404.6.1.4 Electrical interconnection.  An electrical junction box shall be installed within 24 inches (610 mm) of the main electrical service panel and shall be connected to   a capped roof penetration sleeve or a location in the attic that is within 3 feet (914 mm) of the solar-ready zone by a minimum 1 inch (25 mm) nonflexible metallic conduit or permanently installed wire as approved by the code official. Where the interconnection terminates in the attic, location shall be no less than 12 inches (35 mm) above ceiling insulation. Both ends of the interconnection shall be labeled "For Future Solar Electric."

 

R404.6.2 Group R occupancies. Buildings in Group R-2, R-3 and R-4 shall comply with Section C405.15 of the Illinois Commercial Stretch Energy Code.

 

SECTION R405

TOTAL BUILDING PERFORMANCE

 

R405.1 Scope. This section establishes criteria for compliance using total building performance analysis. Such analysis shall include heating, cooling, mechanical ventilation and service water-heating energy only.

 

R405.2 Performance-based compliance. Compliance based on total building performance requires that a proposed design meets all of the following:

 

1.         The requirements of the sections indicated within Table R405.2.

2.         The proposed total building thermal envelope UA, which is the sum of the U-factor times assembly area, shall be less than or equal to the building thermal envelope UA using the prescriptive U-factors from Table R402.1.2 multiplied by 1.10 in accordance with Equation 4-1.

UAProposed design ≤1.10 x UAPrescriptive reference design (Equation 4-1)

The site energy use of the proposed design shall be less than or equal to 71% of the site energy use of the standard reference design.

 

TABLE R405.2

REQUIREMENTS FOR TOTAL BUILDING PERFORMANCE

 

SECTIONa	TITLE
General
R401.3	Certificate
Building Thermal Envelope
R402.1.1	Vapor retarder
R402.2.3	Eave baffle
R402.2.4.1	Access hatches and doors
R402.2.10.1	Crawl space wall insulation installations
R402.4.1.1	Installation
R402.4.1.2	Testing
R402.5	Maximum fenestration U-factor and SHGC
Mechanical
R403.1	Controls
R403.3, including R403.3.1, except Sections R403.3.2, R403.3.3 and R403.3.6	Ducts
R403.4	Mechanical system piping insulation
R403.5.1	Heated water circulation and temperature maintenance systems
R403.5.3	Drain water heat recovery units
R403.6	Mechanical ventilation
R403.7	Equipment sizing and efficiency rating
R403.8	Systems serving multiple dwelling units
R403.9	Snow melt and ice systems
R403.10	Energy consumption of pools and spas
R403.11	Portable spas
R403.12	Residential pools and permanent residential spas
Electrical Power and Lighting Systems
R404.1	Lighting equipment
R404.2	Interior lighting controls
R404.4	Electric Vehicle Power Transfer Infrastructure
R404.5	Electric readiness
R404.6	Renewable energy infrastructure

 

a.        Reference to a code section includes all the relative subsections except as indicated in the table.

 

SECTION R406

ENERGY RATING INDEX COMPLIANCE ALTERNATIVE

 

R406.1 Scope. This section establishes criteria for compliance using an Energy Rating Index (ERI) analysis.

 

R406.2 ERI compliance. Compliance based on the ERI requires that the rated design meets all of the following:

 

1.         The requirements of the sections indicated within Table R406.2.

2.         Maximum ERI of Table R406.5.

 

TABLE R406.2

REQUIREMENTS FOR ENERGY RATING INDEX

 

SECTIONa	TITLE
General
R401.3	Certificate
Building Thermal Envelope
R402.1.1	Vapor retarder
R402.2.3	Eave baffle
R402.2.4.1	Access hatches and doors
R402.2.10.1	Crawl space wall insulation installation
R402.4.1.1	Installation
R402.4.1.2	Testing
Mechanical
R403.1	Controls
R403.3 except Sections R403.3.2, R403.3.3 and R403.3.6	Ducts
R403.4	Mechanical system piping insulation
R403.5.1	Heated water calculation and temperature maintenance systems
R403.5.3	Drain water heat recovery units
R403.6	Mechanical ventilation
R403.7	Equipment sizing and efficiency rating
R403.8	Systems serving multiple dwelling units
R403.9	Snow melt and ice systems
R403.10	Energy consumption of pools and spas
R403.11	Portable spas
R403.12	Residential pools and permanent residential spas
Electrical Power and Lighting Systems
R404.1	Lighting equipment
R404.2	Interior lighting controls
R404.4	Electric Vehicle Power Transfer Infrastructure
R404.5	Electric readiness
R404.6	Renewable energy infrastructure

 

a.         Reference to a code section includes all the relative subsections except as indicated in the table.

 

R406.3Building thermal envelope. The proposed total building thermal envelope UA, which is sum of U- factor times assembly area, shall be less than or equal to the building thermal envelope UA using the prescriptive U-factors from Table R402.1.2 multiplied by 1.10 in accordance with Equation 4-2.

UAProposed design < 1.10 × UAPrescriptive reference design

(Equation 4-2)

 

R406.4 Energy rating index. The Energy Rating Index (ERI) shall be determined in accordance with ANSI/RESNET/ICC 301 The mechanical ventilation rates used for the purpose of determining the ERI shall not be construed to establish minimum ventilation requirements for compliance with this code.

 

Energy used to recharge or refuel a vehicle used for transportation on roads that are not on the building site shall not be included in the ERI reference design or the rated design.

 

R406.5 ERI-based compliance. Compliance based on an ERI analysis requires that the rated proposed design and confirmed built dwelling be shown to have an ERI less than or equal to the appropriate value indicated in Table R406.5 when compared to the ERI reference design.

 

TABLE R406.5

MAXIMUM ENERGY RATING INDEX

 

Climate Zone	Energy Rating Index Without Combustion Equipmenta	Energy Rating Index With Combustion Equipmentb
4	54	51
5	55	50

 

a.      Any building that contains no combustion equipment.

b.      Any building that contains combustion equipment.

 

SECTION R408

ADDITIONAL EFFICIENCY REQUIREMENTS

 

R408.1 Scope. This section establishes additional efficiency requirements to achieve additional energy efficiency in accordance with Section R401.2.1.  Buildings shall comply with either Section R408.2 or Section R408.3

 

R408.2. Heat pump equipment and air tightness option. Buildings shall comply with all of the following:

 

1.         Heating and cooling equipment shall be electric heat pump equipment. In Climate Zone 5A, air-source heat pumps shall meet the following requirements for cold climate heat pumps:

1.1       COP at 5°F (-15°C) ≥ 1.75

1.2       Percent of heating capacity at 5°F (-15°C) ≥ 70% of that at 47°F (8.34°C)

2.         Water heating equipment shall be a heat pump water heater.

3.         The measured air leakage shall be less than or equal to 2.0 Air Change per Hour at 50 Pa (ACH50) with either an Energy Recovery Ventilator (ERV) or Heat Recovery Ventilator (HRV) with a sensible heat recovery efficiency (SRE) no less than 70% at 32°F (0°C) at an airflow greater than or equal to design airflow. The SRE shall be determined from a listed value or from interpolation of listed values. Construction documents shall include documentation of the SRE.

 

R408.3 Additional energy efficiency credit requirements. Additional efficiency measures shall be selected from Table R408.3 that meet or exceed a total of 30 credits. Five additional credits shall be selected for dwelling units with greater than 5,000 square feet (465 m2) of living space floor area located above grade plane. Each measure selected shall meet the relevant subsections of Section R408 and receive credit as specified in Table R408.3 for the specific Climate Zone. Interpolation of credits between measures shall not be permitted.

 

TABLE R408.3

CREDITS FOR ADDITIONAL ENERGY EFFICIENCY

 

Measure Number	Measure Description	Credit Value
		CZ 4	CZ 5
R408.3.1.1 (1)	≥ 2.5% reduction in total UA	1	1
R408.2.1.1 (2)	≥ 5% reduction in total UA	2	3
R408.3.1.1 (3)	> 7.5% reduction in total UA	2	3
R408.3.1.2	0.22 U-factor windows	3	4
R408.3.2 (1)	High performance cooling system option 1	3	3
R408.3.2 (2)	High performance cooling system option 2	3	2
R408.3.2 (3)	High performance gas furnace option 1	5	7
R408.3.2(4)	High performance gas furnace option 2	4	5
R408.3.2(5)	High performance electric heat pump system option 1	21	31
R408.3.2 (6)	High performance electric heat pump system option 2	22	32
R408.3.2 (7)	Ground source heat pump	23	33
R408.3.2 (8)	High performance gas heat pump space heating system option 1	8	11
R408.3.2 (9)	High performance gas heat pump space heating system option 2	11	16
R408.3.3 (1)	Fossil fuel service water heating system	3	2
R408.3.3 (2)	High performance heat pump water heating system	8	6
R408.3.3 (3)	Solar hot water heating system	6	6
R408.3.3 (4)	Compact hot water distribution	2	2
R408.3.4 (1)	More efficient distribution system	10	12
R408.3.4 (2)	100% of ducts in conditioned space	12	15
R408.3.4 (3)	Reduced total duct leakage	1	1
R408.3.5 (1)	2 ACH50 air leakage rate with ERV or HRV installed	10	13
R408.3.5 (2)	2 ACH50 air leakage rate with balanced ventilation	4	5
R408.3.5 (3)	1.5 ACH50 air leakage rate with ERV or HRV installed	12	15
R408.3.5 (4)	1 ACH50 air leakage rate with ERV or HRV installed	14	17
R408.3.6	Energy Efficient Appliances	1	1

 

R408.3.1 Enhanced envelope option.  The building thermal envelope shall meet the requirements of Section R408.3.1.1 or R408.3.1.2.

 

R408.3.1.1 Enhanced envelope performance UA. The proposed total building thermal envelope UA shall be calculated in accordance with Section R402.1.5 and shall meet one of the following:

 

1.         Not less than 2.5% of the total UA of the building thermal envelope.

2.         Not less than 5% of the total UA of the building thermal envelope.

3.         Not less than 7.5% of the total UA of the building thermal envelope.

 

R408.3.1.2 Improved fenestration. Vertical fenestration shall meet a U-factor equal to or less than 0.22.

 

R408.3.2 More efficient HVAC equipment performance option. Heating and cooling equipment shall meet one of the following efficiencies:

Options:

 

1.         Greater than or equal to 6.9 SEER2 and 13.4 EER2 air conditioner.

2.         Greater than or equal to 15.2 SEER2 and 10 EER2 air conditioner.

3.         Greater than or equal to 96 AFUE natural gas furnace.

4.         Greater than or equal to 92 AFUE natural gas furnace.

5.         Greater than or equal to 8.1HSPF2/16 SEER2 electric air source heat pump.

6.         Greater than or equal to 8.5 HSPF2/16.9 SEER2 electric air source heat pump.

7.         Greater than or equal to 3.5 COP ground source heat pump.

8.         Greater than or equal to 120 AFUE gas heat pump space heating system.  The gas heat pump space heating system shall not be configured to provide cooling.

9.         Greater than or equal to 140 AFUE gas heat pump space heating system.  The gas heat pump space heating system shall not be configured to provide cooling.

 

For multiple cooling systems, all systems shall meet or exceed the minimum efficiency requirements in this section and shall be sized to serve 100% of the cooling design load. For multiple heating systems, all systems shall meet or exceed the minimum efficiency requirements in this section and shall be sized to serve 100% of the heating design load.  In Climate Zone 5A, air-source heat pumps shall meet the following requirements for cold climate heat pumps:

 

1.         COP at 5°F (-15°C) ≥ 1.75

2.         Percent of heating capacity at 5°F (-15°C) ≥ 70% of that at 47°F (8.34°C)

 

R408.3.3 Reduced energy use in service water-heating option. The hot water system shall meet one of the following efficiencies:

 

1.         Greater than or equal to 0.82 UEF fossil fuel service water-heating system.

2.         Greater than or equal to 2.9 UEF electric service water-heating system.

3.         Greater than or equal to 3.00 SUEF solar water-heating system with electric backup.

4.         Greater than or equal to 1.80 SUEF solar water-heating system with gas backup.

5.         Compact hot water distribution. For Compact Hot Water Distribution system credit, the volume shall store not more than 16 ounces of water in the nearest source of heated water and the termination of the fixture supply pipe when calculated using section R408.3.3.1 and documented in compliance with Section R408.3.3.2.

 

R408.3.3.1 Water volume determination.  The water volume in the piping shall be calculated in accordance with this section. Water heaters, circulating water systems and heat trace temperature maintenance systems shall be considered to be sources of heated water. The volume shall be the sum of the internal volumes of pipe, fittings, valves, meters and manifolds between the nearest source of heated water and the termination of the fixture supply pipe. The volume in the piping shall be determined from Table R408.3.3.1. The volume contained within fixture shutoff valves, within flexible water supply connectors to a fixture fitting and within a fixture fitting shall not be included in the water volume determination. Where heated water is supplied by a recirculating system or heat-traced piping, the volume shall include the portion of the fitting on the branch pipe that supplies water to the fixture.

 

TABLE R408.3.3.1

INTERNAL VOLUME OF VARIOUS WATER DISTRIBUTION TUBING

OUNCES OF WATER PER FOOT OF TUBE

 

NOMINAL SIZE (inches)	COPPER TYPE M	COPPER TYPE L	COPPER TYPE K	CPVC CTS SDR 11	CPVC SCH 40	CPVC SCH 80	PE- RT SDR 9	COMPOSITE ASTM F1281	PEX CTS SDR 9
⅜	1.06	0.97	0.84	N/A	1.17	-	0.64	0.63	0.64
½	1.69	1.55	1.45	1.25	1.89	1.46	1.18	1.31	1.18
¾	3.43	3.22	2.90	2.67	3.38	2.74	2.35	3.39	2.35
1	5.81	5.49	5.19	4.43	5.53	4.57	3.91	5.56	3.91
1¼	8.70	8.36	8.09	6.61	9.66	8.24	5.81	8.49	5.81
1½	12.18	11.83	11.45	9.22	13.20	11.38	8.09	13.88	8.09
2	21.08	20.58	20.04	15.79	21.88	19.11	13.86	21.48	13.86

For SI: 1 foot = 304.8 mm, 1 inch = 25.4 mm, 1 liquid ounce = 0.030L, 1 oz/ft2 = 305.15 g/m2.

N/A = Not available

 

R408.3.3.2 Water volume documentation. Where compliance with Section R408.3.3(5) is required, construction documentation or final field inspection shall verify that the compact hot water distribution system meets the prescribed limit in Section R408.3.3(5) with one of the following:

 

1.         Referencing ounces of water per foot of tube on plans as per Table R408.3.3.1.

2.         Referencing ounces of water per foot of tube installed as per Table R408.3.3.1.

3.         In accordance with Department of Energy's Zero Energy Ready Home National Specification (Rev. 07 or higher) footnote on Hot water delivery systems.

 

R408.3.4 More efficient duct thermal distribution system option. The thermal distribution system shall meet one of the following efficiencies:

 

1.         100% of ductless thermal distribution system or hydronic thermal distribution system located completely inside the building thermal envelope.

2.         100% of duct thermal distribution system located in conditioned space as defined by Section R403.3.2.

3.         When ducts are located outside conditioned space, the total leakage of the ducts, measured in accordance with R403.3.5, shall be in accordance with one of the following:

3.1.      Where the air handler is installed at the time of testing, 2.0 cubic feet per minute (0.94 L/s) per 100 square feet (9.29 m) of conditioned floor area.

3.2       Where the air handler is not installed at the time of testing, 1.75 cubic feet per minute (0.83 L/s) per 100 square feet (9.29 m) of conditioned floor area.

 

R408.3.5 Improved air sealing and efficient ventilation system option. The measured air leakage rate shall be one of the following:

 

1.         Less than or equal to 2.0 ACH50, with either an Energy Recovery Ventilator (ERV) or Heat Recovery Ventilator (HRV) installed.

2.         Less than or equal to 2.0 ACH50, with balanced ventilation as defined in Section 202 of the 2021 International Mechanical Code.

3.         Less than or equal to 1.5 ACH50, with either an ERV or HRV installed.

4.         Less than or equal to 1.0 ACH50, with either an ERV or HRV installed.

 

Minimum HRV and ERV requirements, measured at the lowest tested net supply airflow, shall be greater than or equal to 75% Sensible Recovery Efficiency (SRE), greater than or equal to 1.2 cubic feet per minute per watt (0.03 m3/min/watt) and shall not use recirculation as a defrost strategy. In addition, the ERV shall be greater than or equal to 50% Latent Recovery/Moisture Transfer (LRMT).

 

R408.3.6 Energy efficient appliances. Appliances installed in a dwelling unit shall meet the product energy efficiency specifications listed in Table R408.3.6, or equivalent energy efficiency specifications. The three appliance types from Table R408.3.6 shall be installed for compliance with this section.

 

TABLE R408.3.6 MINIMUM EFFICIENCY REQUIREMENTS: APPLIANCES

 

Appliance	Efficiency Improvement	Test Procedure
Refrigerator	Maximum Annual Energy Consumption (AEC) No greater than 620 kWh/yr	10 CFR 430, Subpart B, Appendix A
Dishwasher	Maximum Annual Energy Consumption (AEC) No greater than 270 kWh/yr	10 CFR 430, Subpart B, Appendix C1
Clothes Washer and Clothes Dryer	Maximum Annual Energy Consumption (AEC) for Clothes Washera No greater than 130 kWh/yr Integrated Modified Energy Factor (IMEF) > 1.84 cu.ft/kWh/cycle	10 CFR 430 Subpart B, Appendix J2 and 10 CFR 430, Subpart B, Appendices D1 and D2

a.         Credit for Clothes Washer and Clothes Dryer pair is based on Clothes Washer efficiency.

 

CHAPTER 6[RE]

REFERENCED STANDARDS

 

ASME	American Society of Mechanical Engineers Two Park Avenue New York, NY  10016-5990
BPVC	Boiler and Pressure Vessel Code
CTA	Consumer Technology Association Technology & Standards Department 1919 S Eads Street Arlington, VA  22202
ANSI/CTA-2045-B – 2018	Modular Communications Interface for Energy Management
ANSI/CTA-2045-A – 2018	Modular Communications Interface for Energy Management
IEC	IEC Regional Centre for North America 446 Main Street 16th Floor Worcester, MA  01608
IEC Regional Centre for North America.	IEC 62746-10-1 - 2018: Systems interface between customer energy management system and the power management system - Part 10-1: Open automated demand response
OpenADR	OpenADR Alliance 111 Deerwood Road, Suite 200 San Ramon, CA  94583
OpenADR Alliance.	OpenADR 2.0a and 2.0b – 2019: Profile Specification Distributed Energy Resources
AHRI	Air-Conditioning, Heating, & Refrigeration Institute 2111 Wilson Blvd, Suite 500 Arlington, VA  22201
AHRI 1380-2019     AHRI 1430-2022 (I-P)	Demand Response through Variable Capacity HVAC Systems in Residential and Small Commercial Applications Demand Flexible Electric Storage Water Heaters

 

SECTION R502

ADDITIONS

 

R502.3 Prescriptive compliance. Additions shall comply with Sections R502.3.1 through R502.3.5.

 

R502.3.1 Building envelope. New building envelope assemblies that are part of the addition shall comply with Sections R402.1, R402.2, R402.3.1 through R402.3.5, and R402.4.

 

Exception: New envelope assemblies are exempt from the requirements of Section R402.4.1.2.

 

R502.3.2 Heating and cooling systems. HVAC ducts newly installed as part of an addition shall comply with Section R403.

 

Exception: Where ducts from an existing heating and cooling system are extended to an addition.

 

R502.3.3 Service hot water systems. New service hot water systems that are part of the addition shall comply with Section R403.5.

 

R502.3.4 Lighting. New lighting systems that are part of the addition shall comply with Section R404.1.

 

R502.3.5 Additional Efficiency Requirements. Additions shall comply with sufficient measures from Table R408.3 to achieve not less than 10 credits. Alterations to the existing building that are not part of the addition, but permitted with the addition, shall be permitted to be used to achieve this requirement.

 

Exceptions:

 

1.         Additions that increase the building’s total conditioned floor area by less than 25%.

2.         Additions that do not include the addition or replacement of equipment covered in Sections R403.5 or R403.7.

3.         Additions that do not contain conditioned space.

4.         Where the addition alone or the existing building and addition together comply with Section R405 or R406.

 

SECTION R503

ALTERATIONS

 

R503.1.1.2 Roof replacement.  Insulation shall comply with Section R402.1. Alternatively, where limiting conditions prevent compliance with Section R402.1, an approved design that minimizes deviation from Section R402.1 shall be provided for the following alterations:

 

1.         Roof replacements or a roof alteration that includes removing and replacing the roof covering where the roof assembly includes insulation entirely above the roof deck. Where limiting conditions require use of an approved design to minimize deviation from Section R402.1 for a Group R-2 building, a registered design professional or other approved source shall provide construction documents that identify the limiting conditions and the means to address them.

 

R503.1.2 Heating and cooling systems. New heating and cooling and duct systems that are part of the alteration shall comply with Section R403 and this section. HVAC ducts newly installed as part of an alteration shall comply with Section R403. Alterations to heating, cooling and duct systems shall comply with this section.

 

R503.1.2.1 Ducts. HVAC ducts newly installed as part of an alteration shall comply with Section R403.

 

Exception: Where ducts from an existing heating and cooling system are extended to an addition.

 

R503.1.2.2 System sizing. New heating and cooling equipment that is part of an alteration shall be sized in accordance with Section R403.7 based on the existing building features as modified by the alteration.

 

Exception: Where it has been demonstrated to the code official that compliance with this section would result in heating or cooling equipment that is incompatible with the remaining portions of the existing heating or cooling system.

 

R503.1.2.3 Duct leakage. Where an alteration includes any of the following, ducts shall be tested in accordance with Section R403.3.5 and shall have a total leakage less than or equal to 12.0 cubic feet per minute (339.9 L/min) per 100 square feet (9.29 m2) of conditioned floor area:

 

1.         Where 25% or more of the registers that are part of the duct system are relocated.

2.         Where 25% or more of the total length of all ducts in the system are relocated.

3.         Where the total length of all ducts in the system is increased by 25% or more.

 

Exception: Duct systems located entirely inside a conditioned space in accordance with Section R403.3.2.

 

R503.1.2.4 Controls New heating and cooling equipment that are part of the alteration shall be provided with controls that comply with Sections R403.1 and R403.2.

 

(Source:  Added at 48 Ill. Reg. 14276, effective January 1, 2025)