Title:71 Part:600

PART 600 ILLINOIS ENERGY CONSERVATION CODE : Sections Listing

TITLE 71: PUBLIC BUILDINGS, FACILITIES AND REAL PROPERTY
CHAPTER I: CAPITAL DEVELOPMENT BOARD
SUBCHAPTER d: ENERGY CODES
PART 600 ILLINOIS ENERGY CONSERVATION CODE

SUBPART A: GENERAL

Section 600.100 Definitions
Section 600.110 Adoption and Modification of the Code
Section 600.120 Illinois Energy Conservation Advisory Council
Section 600.130 Revisions to the Code

SUBPART B: STATE FUNDED FACILITIES

Section 600.200 Standards for State Funded Facilities
Section 600.210 Exemptions
Section 600.220 Compliance

SUBPART C: PRIVATELY FUNDED COMMERCIAL FACILITIES

Section 600.300 Standards for Privately Funded Commercial Facilities
Section 600.310 Exemptions
Section 600.320 Local Jurisdiction
Section 600.330 Compliance
Section 600.340 Application to Home Rule Units

SUBPART D: RESIDENTIAL BUILDINGS

Section 600.400 Standards for Residential Buildings
Section 600.410 Exemptions
Section 600.420 Local Jurisdiction
Section 600.430 Compliance
Section 600.440 Application to Home Rule Units
Section 600.APPENDIX A Supplanted and Additional 2021 International Energy Conservation Code Sections

AUTHORITY: Implementing and authorized by the Capital Development Board Act [20 ILCS 3105] and the Energy Efficient Building Act [20 ILCS 3125].

SOURCE: Adopted by emergency rulemaking at 28 Ill. Reg. 11355, effective July 26, 2004, for a maximum of 150 days; emergency rules expired December 22, 2004; adopted at 29 Ill. Reg. 777, effective January 1, 2005; new Part adopted by emergency rulemaking at 29 Ill. Reg. 5736, effective April 8, 2005, for a maximum of 150 days; emergency expired September 4, 2005; emergency rulemaking repealed at 29 Ill. Reg. 6093, effective April 18, 2005, for a maximum of 150 days; emergency expired September 14, 2005; old Part repealed at 29 Ill. Reg. 16414 and new Part adopted at 29 Ill. Reg. 14790, effective April 8, 2006; amended at 31 Ill. Reg. 14422, effective October 9, 2007; emergency amendment at 33 Ill. Reg. 12407, effective August 18, 2009, for a maximum of 150 days; amended at 33 Ill. Reg. 16702, effective November 23, 2009; emergency rulemaking at 34 Ill. Reg. 2582, effective January 29, 2010, for a maximum of 150 days; emergency expired June 27, 2010; amended at 34 Ill. Reg. 11398, effective July 26, 2010; amended at 37 Ill. Reg. 789, effective January 11, 2013; amended at 37 Ill. Reg. 12822, effective July 23, 2013; amended at 40 Ill. Reg. 2754, effective January 20, 2016; amended at 43 Ill. Reg. 8707, effective August 5, 2019; amended at 47 Ill. Reg. 17974, effective November 27, 2023.

SUBPART A: GENERAL

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:

"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" or "Code" means:

With respect to the State facilities covered by Subpart B:

This Part, all additional requirements incorporated within Subpart B (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;

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

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:

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.

"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 47 Ill. Reg. 17974, effective November 27, 2023)

Section 600.110 Adoption and Modification of the Code

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 State and 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 Code to all commercial and residential structures in Illinois, and to assist local code officials with enforcing the requirements of the Code. The 2021 Illinois Energy Conservation Code will become effective on adoption of this rulemaking.

b) This Code as described in Subpart B (State facilities) is effective July 26, 2004. This Code as described in Subpart C (privately-funded commercial facilities) is effective April 8, 2007. The Code as described in Subpart D (residential buildings) is effective January 29, 2010.

c) Application of the Code

1) State Facilities. The Code as described in Subpart B of this Part applies to all State facilities for which money has been appropriated or authorized by the General Assembly.

2) Privately Funded Commercial Facilities and Residential Buildings. The Code 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.

d) 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 47 Ill. Reg. 17974, effective November 27, 2023)

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 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 his or her 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.

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 47 Ill. Reg. 17974, effective November 27, 2023)

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].

SUBPART B: STATE FUNDED FACILITIES

Section 600.200 Standards for State Funded Facilities

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 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 15 of the EEB Act, when applying the Code to State funded 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 47 Ill. Reg. 17974, effective November 27, 2023)

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 Energy Conservation Code for State facilities as described by this Subpart B shall be demonstrated by submission of:

a) the compliance forms published in the ASHRAE 90.1 User's Manual;

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 43 Ill. Reg. 8707, effective August 5, 2019)

SUBPART C: PRIVATELY FUNDED COMMERCIAL FACILITIES

Section 600.300 Standards for Privately Funded Commercial Facilities

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 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 47 Ill. Reg. 17974, effective November 27, 2023)

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 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. The AHJ is authorized to enforce a building code that differs with the 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 40 Ill. Reg. 2754, effective January 20, 2016)

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).

b) Minimum compliance shall be demonstrated by submission of:

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].

(Source: Amended at 33 Ill. Reg. 16702, effective November 23, 2009)

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)

SUBPART D: RESIDENTIAL BUILDINGS

Section 600.400 Standards for Residential Buildings

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 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 47 Ill. Reg. 17974, effective November 27, 2023)

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;

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

(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 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 47 Ill. Reg. 17974, effective November 27, 2023)

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.

b) Minimum compliance shall be demonstrated by submission of:

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].

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

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 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 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; and

3) a municipality with a population of 1,000,000 or more. [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 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. [20 ILCS 3125/45(c)]

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

Section 600.APPENDIX A Supplanted and Additional 2021 International Energy Conservation Code Sections

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 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.

C101.1.2 Adoption. The Board shall adopt amendments to this Code within 12 months after publication of changes to the 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.

C101.1.3 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 – means 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 or AHJ − means the organization, officer or individual responsible for approving equipment, materials, an installation or procedure.

Board − means the Illinois Capital Development Board.

Council − means the Illinois Energy Conservation Advisory Council whose purpose is to recommend modifications to the Illinois Energy Conservation Code.

Demand Response Signal - means a signal that indicates a price or a request to modify electricity consumption for a limited time period.

Demand Responsive Control – means a control capable of receiving and automatically responding to a demand response signal.

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

Photosynthetic Photon Efficacy (PPE) – means 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 equation either (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- 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 west-oriented and east-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 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 C402.5.8. 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 Section C406.2 and Section C406.13.

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

Modify Table C406.1(1) as follows:

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

Climate Zone:	4A	5A
C406.13 HVAC demand responsive controls	2	2
C406.14 Water heating demand responsive controls	1	1

Modify Table C406.1(2) as follows:

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

Climate Zone:	4A	5A
C406.13 HVAC demand responsive controls	4	3
C406.14 Water heating demand responsive controls	1	1

Modify Table C406.1(3) as follows:

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

Climate Zone:	4A	5A
C406.13 HVAC demand responsive controls	4	4
C406.14 Water heating demand responsive controls	1	1

Modify Table C406.1(4) as follows:

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

Climate Zone:	4A	5A
C406.13 HVAC demand responsive controls	4	3
C406.14 Water heating demand responsive controls	x	x

Modify Table C406.1(5) as follows:

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

Climate Zone:	4A	5A
C406.13 HVAC demand responsive controls	3	3
C406.14 Water heating demand responsive controls	2	2

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 Section 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 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 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

SECTION^a	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 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 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 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

BPVC

Boiler and Pressure Vessel Code

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
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 016808
IEC 62746-10-1 - 2018	Systems interface between customer energy management system and the power management system – Part 10-1: Open automated demand response

CHAPTER 1 [RE]

SCOPE AND ADMINISTRATION

SECTION R101

SCOPE AND GENERAL REQUIREMENTS

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

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

R101.1.2 Adoption. The Board shall adopt amendments to this Code within 12 months after publication of changes to the 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.

R101.1.3 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 building 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 when those 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:

i) 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;

ii) 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; and

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

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 − means 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 or AHJ − means the organization, officer or individual responsible for approving equipment, materials, an installation or procedure.

Board − means the Illinois Capital Development Board.

Council − means the Illinois Energy Conservation Advisory Council whose purpose is to recommend modifications to the Illinois Energy Conservation Code.

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

Local Exhaust − means an exhaust system that uses one or more fans to exhaust air from a specific room or rooms within a dwelling.

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.

Whole House Mechanical Ventilation System – means 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 R405.3 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 INSULATION AND FENESTRATION REQUIREMENTS

CLIMATE ZONE

CEILING

U-FACTOR

4 except

Marine

0.026

5 and

Marine 4

0.026

Modify Table R402.1.3 as follows:

TABLE R402.1.3

INSULATION MINIMUM R-VALUES AND FENESTRATION REQUIREMENTS BY COMPONENTa

CLIMATE ZONE

CEILING

R -VALUE

4 except Marine

5 and

Marine 4

R402.2.1 Roof/Ceilings with attic spaces. 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. Where Section R402.1.3 requires R-60 insulation in the ceiling, installing R-49 over 100 percent of the ceiling area requiring insulation shall satisfy the requirement for R-60 insulation wherever the full height of uncompressed R-49 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 Attic Spaces. 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 of conditioned floor area, the allowable duct leakage with the air-handler installed shall be 60 cubic feet per minute or less.

2. Postconstruction 5test: 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 of conditioned floor area, the allowable duct leakage shall be 60 cubic feet per minute 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 of conditioned floor area, the allowable duct leakage with the air-handler installed shall be 60 cubic feet per minute or less.

R403.6 Mechanical Ventilation. The building or dwelling unit 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), by Equation 4-0 or by 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. When 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 air flow 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 RATES^a
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.

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 co-requisites, 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, the following item must be provided to the code official:

1. A Phius 2021 (or later) project certificate.

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 47 Ill. Reg. 17974, effective November 27, 2023)