Energy Code Adoption by State
NAHB has published a detailed catalogue of the model energy codes adopted and amended at the state and local level throughout the country along with information about the processes and governmental bodies that update these codes.
Many states choose to amend model building codes to address local conditions. Information on the most impactful amendments (if applicable) as compared to the model code edition adopted by the state can be found here.
Several states do not adopt any mandatory statewide residential energy code (typically referred to as “home rule” states), though there are often codes adopted by local jurisdictions. Some states choose to develop their own energy codes that are not based on any edition of the IECC.
Hover your cursor over a state in the map below for summary information about its residential energy code and scroll down for more detailed information about each state’s residential energy code.
Alabama Residential Energy Code
Code Language
Model Code Edition: 2015 IECC
Key Amendments: PDF Summary
Effective Date: January 1, 2016
State Mandate: Mandatory statewide code
IECC Climate Zones: 2, 3
Local Permission: There is no clarification in the state code about whether local jurisdictions are allowed to amend the code.
Alabama Licensing Board for General Contractors - https://genconbd.alabama.gov/default.aspx
Future Code Adoption: “By December 31, 2025, the Alabama Commercial Energy Code Advisory Committee shall submit to the Alabama Licensing Board for General Contractors for adoption the proposed Alabama Commercial Energy Code” AL Code § 34-8-55 (2024)
Advocacy and Other Resources
IECC General Overview: International Energy Conservation Code (IECC), 2024 IECC Overview Series (NAHB members-only)
State HBA: Home Builders Association of Alabama
Other NAHB Links: Code Adoption Kits, IECC Cost-Effectiveness Studies
Alaska Building Energy Efficiency Standard (BEES)
Code Language
Model Code Edition: 2018 IECC
Key Amendments: PDF Summary
State Mandate: No statewide code. Alaska is a home rule state that does not have a mandatory statewide residential energy code. However, local jurisdictions may adopt their own codes.
IECC Climate Zones: 5, 6, 7, 8
Alaska Housing Finance Corporation
https://www.ahfc.us/pros/builders
Advocacy and Other Resources
IECC Overview: International Energy Conservation Code (IECC)
State HBA: Alaska State Home Builders Association
Residential energy codes adopted by a sample of Alaska local jurisdictions:
- Population (2024): 289,600
- Code: Anchorage Local Amendments to the International Energy Conservation Code 2018 Edition, based on the 2018 IECC with local amendments
- Effective Date: September 14, 2023
- Population (2024): 31,732
- Code: City of Fairbanks Local Amendments to the 2018 International Energy Conservation Code, based on the 2018 IECC with local amendments
- Population (2024): 31,572
- Code: No local energy code adopted
- Effective Date: N/A
No Statewide Code
Arizona is a home rule state that does not have a mandatory statewide residential energy code. However, local jurisdictions may adopt their own codes.
IECC Climate Zones: 2, 3, 4, 5
State HBA: HBA of Central Arizona
Residential energy codes adopted by a sample of Arizona local jurisdictions:
- Population (2024): 1,673,164
- Code: 2024 Phoenix Building Construction Code (PBCC), based on the2024 IECC with local amendments
- Effective Date: 8/1/2025
- Population (2024): 554,013
- Code: Tucson Amendments to the 2018 International Energy Conservation Code, based on the 2018 IECC with local amendments
- Effective Date: “To remain active until further notice”
- Population (2024): 103,559
- Code: Yuma Amendments to the 2009 International Energy Conservation Code, based on the 2009 IECC with local amendments
- Effective Date: 12/1/2013
- Population (2024): 77,539
- Code: Flagstaff City Code, Title 4 Building Regulations, 2018 IECC Amendments, based on the 2018 IECC with local amendments
- Effective Date: 7/19/2019
- Population (2024): 44,710
- Code: City of Sierra Vista Amendments to the 2006 IECC for Residential Construction, based on the 2006 IECC with local amendments
- Effective Date: 7/1/2023
- Population (2024): 19,965
- Code: None – The city adopted the 2015 City of Nogales Amendments to Building and Safety Codes which do not reference the IECC
- Effective Date: N/A
2014 Arkansas Energy Code for New Building Construction
Code Language
Model Code Edition: 2009 IECC
Key Amendments: PDF Summary
Effective Date: January 1, 2015
State Mandate: Mandatory statewide code
IECC Climate Zones: 3, 4
Local Permission: Nothing in the authorizing legislation for the Energy Office mentions how often a new code should be created: A.C.A. § 15-10-205. Local jurisdictions are permitted to adopt amendments to the state code.
Arkansas Energy Office
https://www.adeq.state.ar.us/energy/initiatives/building.aspx
Advocacy and Other Resources
IECC General Overview: International Energy Conservation Code (IECC)
State HBA: Arkansas Home Builders Association
2025 California Energy Code
Code Language
Model Code Edition: State-developed code
State Mandate: Mandatory statewide
Local Permission: Local jurisdictions are permitted (with permission from the state) to adopt energy standards more stringent than the state-developed code.
IECC Climate Zones: 2B, 3B, 3C, 4B, 4C, 5B, 6B (note: California’s code defines its own climate zones)
Adoption Date: July 2025
Effective Date: January 1, 2026
Future Adoption: In July 2025, the California legislature adopted AB 130, which prevents the state of California from considering, approving, or adopting any changes to residential building codes (other than the already-approved 2025 state code) until June 1, 2031, except in emergency situations or in the case of wildfire mitigation. Further, the bill prevents local municipalities from amending their code during the same period.
California Building Standards Commission
State HBA: California Building Industry Association
2022 Connecticut State Building Code
Code Language
Model Code Edition: 2021 IECC
Key Amendments: PDF Summary
Effective Date: 10/1/2022
State Mandate: Mandatory statewide
IECC Climate Zones: 5
Local Permission: The state building code, including any amendments to the code adopted by the state building inspector and Codes and Standards Committee, is the building code for all towns, cities, and boroughs in the state. Any town, city, borough, or interested person may propose amendments to the state building code. Once approved, the amendments become part of the state building code and are applied statewide.
Future Adoptions: The state is expected to adopt the 2026 Connecticut State Building Code based on the 2024 IECC in July 2026, with an effective date of October 1, 2026. For additions, the code allows thermal envelope assemblies an exception to air leakage testing if all air barrier and insulation installation items in Table R402.5.1.1 are field verified. The state building inspector is permitted to deem the National Green Building Standard (NGBS) an approved above-code program.
State Building Inspector and Codes and Standards Committee
https://portal.ct.gov/das/office-of-state-building-inspector/codes-and-standards-committee
State HBA: Home Builders and Remodelers Association of Connecticut
Regulations for State Energy Conservation Code
Code Language
Model Code Edition: 2018 IECC
Key Amendments: PDF Summary
Effective Date: June 11, 2020
State Mandate: Mandatory statewide
IECC Climate Zones: 4
Department of Natural Resources and Environmental Control
https://dnrec.delaware.gov/
State HBA: Home Builders Association of Delaware
2017 District of Columbia Energy Conservation Code
Code Language
Model Code Edition: 2015 IECC
Key Amendments: PDF Summary
Effective Date: May 29, 2020
State Mandate: Mandatory districtwide
IECC Climate Zones: 4
Construction Codes Coordinating Board
https://dob.dc.gov/service/construction-codes-coordinating-board-1
2023 Florida Building Code, Energy Conservation
Code Language
Model Code Edition: 2021 IECC
Key Amendments: PDF Summary
Effective Date: Dec. 31, 2023
State Mandate: Mandatory statewide
IECC Climate Zones: 2, 1
Local Permission: Local governments may, subject to the limitations in this section and not more than once every 6 months, adopt amendments to the technical provisions of the Florida Building Code that apply solely within the jurisdiction of such government and that provide for more stringent requirements than those specified in the Florida Building Code.
Florida Building Commission
https://floridabuilding.org/c/default.aspx
Future Code Adoption: The 2026 Florida Building Code, with updates to energy conservation requirements, will become effective Dec. 31, 2026.
State HBA: Florida Home Builders Association
Georgia State Minimum Standard Energy Code
Code Language
Model Code Edition: 2015 IECC
Key Amendments: PDF Summary
Effective Date: January 1, 2023
State Mandate: Mandatory statewide code
IECC Climate Zones: 2, 3, 4
Local Permission: The governing authority of any municipality or county in this state is authorized to enforce and/or adopt and enforce the state minimum standard codes; to provide for the local administration of such codes; In addition, since Georgia law gives these codes statewide applicability, local governments should not adopt the mandatory codes themselves. Local governments must, however, adopt administrative procedures in order to enforce them (O.C.G.A. Section 8-2-25(a)). However, the local government can choose which of the mandatory codes it wishes to locally enforce. In the event that the governing authority of any municipality or county finds that the state minimum standard codes do not meet its needs, the local government may provide requirements not less stringent than those specified in the state minimum standard codes
2015 International Energy Conservation Code Task Force
https://dca.georgia.gov/community-assistance/construction-codes/energy-codes-web-hub
Future Code Adoption: The State Codes Advisory Committee convened on June 24, 2025, and voted to recommend that the Georgia Department of Community Affairs Board adopt a series of codes.
State HBA: Home Builders Association of Georgia
Idaho Energy Conservation Code (2020 Edition)
Code Language
Model Code Edition: 2018 IECC
Key Amendments: PDF Summary
Effective Date: January 1, 2021
State Mandate: Mandatory statewide
IECC Climate Zones: 5, 6
Local Permission: Local governments that issue building permits and perform building code enforcement activities shall, by ordinance effective January 1 of the year following the adoption by the Idaho building code board, adopt the following codes [IBC, IRC, IECC] as published by the International Code Council together with any amendments or revisions set forth in section 39-4109, Idaho Code. -- Except as provided in this subsection, local governments may amend by ordinance the adopted codes or provisions of referenced codes to reflect local concerns, provided such amendments establish at least an equivalent level of protection to that of the adopted building code. no amending accessibilty provisions nothing from the IRC or IECC that hasn't already been adopted by the state can amend the IRC's part I, II, III, and IX
Idaho Building Code Board & Factory Built Structures Board
https://dopl.idaho.gov/bld/
Future Code Adoption: Any edition of the building codes adopted by the board will take effect on January 1 of the year following its adoption
State HBA: Idaho Home Builders Association
Illinois Energy Conservation Code
Code Language
Model Code Edition: 2021 IECC
Key Amendments: PDF Summary
Effective Date: January 1, 2024
State Mandate: Mandatory statewide
IECC Climate Zones: 4, 5
Local Permission: Illinois Energy Conservation Stretch Code, based on the 2021 IECC. 2025 stretch code is under development, based on the 2024 IECC. 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 Act.
State HBA: Home Builders and Remodelers Association of Illinois
Iowa State Energy Code
Code Language
Model Code Edition: 2012 IECC
Key Amendments: PDF Summary
Effective Date: April 12, 2014
State Mandate: Mandatory statewide
IECC Climate Zones: 5, 6
Local Permission: The state building code is applicable in each governmental subdivision of the state in which the governing body has enacted an ordinance accepting the applicability of the code and has filed a certified copy of the ordinance in the office of the commissioner. A governmental subdivision in which the state building code is applicable may by ordinance, at any time after one year has elapsed since the code became applicable, withdraw from the application of the code.
State Building Code Advisory Council
https://dial.iowa.gov/boards-0/building-code
State HBA: Home Builders Association of Iowa
2009 International Energy Conservation Code (for use with the Kentucky Residential Code only)
Code Language
Model Code Edition: 2009 IECC
Key Amendments: PDF Summary
State Mandate: Mandatory statewide
IECC Climate Zones: 4
Kentucky Department of Housing, Buildings and Construction, with the advice of the Housing, Builidings and Construction Advisory Committee
https://dhbc.ky.gov/
Future Code Adoption: Kentucky has adopted the 2012 IECC for commercial construction.
State HBA: Home Builders Association of Kentucky
Louisiana Uniform Construction Code
Code Language
Model Code Edition: 2021 IECC
Key Amendments: PDF Summary
Effective Date: March 1, 2024
State Mandate: Mandatory statewide
IECC Climate Zones: 2
Louisiana State Uniform Construction Code Council
https://lsuccc.dps.louisiana.gov/
State HBA: Louisiana Home Builders Association
Maine Uniform Building and Energy Code - Residential Building Code for One and Two-Family Dwellings in Maine
Code Language
Model Code Edition: 2021 IECC
Key Amendments: PDF Summary
Effective Date: April 7, 2025
State Mandate: Mandatory statewide
IECC Climate Zones: 6, 7
Local Permission: As of July 1, 2020, the codes and standards board will adopt, amend and maintain an appendix to the Maine Uniform Building and Energy Code as an optional part of the code that contains energy conservation and efficiency requirements that are based on established national voluntary efficiency standards that exceed the energy code requirements established in the Maine Uniform Building and Energy Code. The appendix must be made available for voluntary adoption by any municipality. The board shall maintain a list of municipalities that have voluntarily adopted the appendix to the Maine Uniform Building and Energy Code on its publicly accessible website
Technical Building Codes and Standards Board
https://www.maine.gov/dps/fmo/building-codes/technical-codes-standards-board
State HBA: Home Builders and Remodelers Association of Maine
Massachusetts State Building Code, Tenth Edition, Residential Volume, Chapter R11: Energy Efficiency
Code Language
Model Code Edition: 2021 IECC
Key Amendments: PDF Summary
Effective Date: October 11, 2024
State Mandate: Mandatory statewide
IECC Climate Zones: 5
Local Permission: If the board finds that more restrictive standards are reasonably necessary because of special conditions prevailing within such city or town and that such standards conform with accepted national and local engineering and fire prevention practices, with public safety and with the general purposes of a statewide building code, the board may, after notice to said board of selectmen or mayor, and after a public hearing, adopt rules and regulations, impose conditions in connection with the adoption thereof and terminate such rules and regulations at such time and in such manner as the board may deem necessary, desirable or proper.
Board of Building Regulations and Standards
https://www.mass.gov/orgs/board-of-building-regulations-and-standards
State HBA: Home Builders & Remodelers Association of Massachusetts
2021 Michigan Commercial Energy Code
Code Language
Model Code Edition: 2021 IECC
Key Amendments: PDF Summary
Effective Date: April 22, 2025
State Mandate: Mandatory statewide
IECC Climate Zones: 5, 6, 7
Michigan Construction Code Commission
https://www.michigan.gov/lara/bureau-list/bcc/boards-commissions/construction-code-commission_including-appeal-review-panel
State HBA: Home Builders Association of Michigan
2020 Minnesota Residential Energy Code
Code Language
Model Code Edition: 2012 IECC
Key Amendments: PDF Summary
Effective Date: February 14, 2015
State Mandate: Mandatory statewide
IECC Climate Zones: 6, 7
Local Permission: (b) The State Building Code supersedes the building code of any municipality. a municipality must not by ordinance, or through development agreement, require building code provisions regulating components or systems of any structure that are different from any provision of the State Building Code. This subdivision does not prohibit a municipality from enacting or enforcing an ordinance requiring existing components or systems of any structure to be maintained in a safe and sanitary condition or in good repair, but not exceeding the standards under which the structure was built, reconstructed, or altered, or the component or system was installed, unless specific retroactive provisions for existing buildings have been adopted as part of the State Building Code. A municipality may, with the approval of the state building official, adopt an ordinance that is more restrictive than the State Building Code where geological conditions warrant a more restrictive ordinance. Municipalities have to adopt the state building code by ordinance to enforce it, this is a map of counties which have adopted the 2020 Minnesota Building Codes: https://www.dli.mn.gov/sites/default/files/pdf/bc_map_county_jurisdiction.pdf
Construction Codes Advisory Council
https://www.dli.mn.gov/about-department/boards-and-councils/construction-codes-advisory-council
State HBA: Builders Association of Minnesota
2021 International Energy Conservation Code
Key Amendments: PDF Summary
Effective Date: June 20, 2022
State Mandate: Mandatory statewide
IECC Climate Zones: 6
Local Permission: A county, city, or town with a building code enforcement program may, as part of its building code or by town ordinance or resolution, adopt voluntary energy conservation standards for new construction for the purpose of providing incentives to encourage voluntary energy conservation. The incentive-based standards adopted may exceed any applicable energy conservation standards contained in the state building code. -- (2) (a) Except as provided in subsection (2)(b), a county, city, or town may not adopt or enforce a building code that is more stringent than the building code adopted by the department or as required by state law. (b) A county, city, or town may, as part of its building code or by town ordinance or resolution, adopt voluntary energy conservation standards for new construction for the purpose of providing incentives to encourage voluntary energy conservation. The incentive-based energy conservation standards adopted may exceed any applicable energy conservation standards contained in the state building code. New construction is not required to meet local standards that exceed state energy conservation standards unless the building contractor elects to receive a local incentive.
Montana Building Codes Council
https://bsd.dli.mt.gov/building-codes-permits/building-codes-council
Future Code Adoption: Future meetings - https://bsd.dli.mt.gov/building-codes-permits/meetings
State HBA: Montana Building Industry Association
Nebraska Energy Code
Code Language
Model Code Edition: 2018 IECC
Key Amendments: PDF Summary
Effective Date: July 1, 2020
State Mandate: Mandatory statewide
IECC Climate Zones: 5
Local Permission: Any energy code adopted by each locality must be "equivalent" (as deemed by the State Energy Office). If the energy code is not equivalent, it must justify these changes to the State Energy Office and can only enforce this local code once the State Energy Office accepts this change.
State HBA: Nebraska State Home Builders Association
2018 International Energy Conservation Code (IECC) with NH Amendments
Code Language
Model Code Edition: 2018 IECC
Key Amendments: PDF Summary
Effective Date: July 1, 2024
State Mandate: Mandatory statewide
IECC Climate Zones: 5, 6
State Building Code Review Board
https://firemarshal.nhdoit.acsitefactory.com/laws-rules-regulatory/state-fire-building-codes
State HBA: New Hampshire Home Builders Association
2021 New Mexico Residential Energy Conservation Code
Code Language
Model Code Edition: 2021 IECC
Key Amendments: PDF Summary
Effective Date: January 30, 2024
State Mandate: Mandatory statewide
IECC Climate Zones: 3, 4, 5
Construction Industries Commission
https://www.rld.nm.gov/construction-industries/committees-commissions/
State HBA: New Mexico Home Builders Association
2020 Energy Conservation Construction Code of New York State
Code Language
Model Code Edition: 2018 IECC
Key Amendments: PDF Summary
Effective Date: May 12, 2020
State Mandate: Mandatory statewide
IECC Climate Zones: 4, 5, 6
Local Permission: The Code Council must approve any local standards and ensure they are more restrictive. Local municipalities are empowered by Executive Law §379
State Fire Prevention and Building Code Council
https://dos.ny.gov/code/code-development
Future Code Adoption: Upcoming meeting info
State HBA: New York State Builders Association
North Carolina State Building Code
Code Language
Model Code Edition: 2015 IECC
Key Amendments: PDF Summary
Effective Date: January 1, 2019
State Mandate: Mandatory statewide
IECC Climate Zones: 3, 4, 5
Local Permission: "Except as otherwise provided in this section, the North Carolina State Building Code shall apply throughout the State, from the time of its adoption" "However, any political subdivision of the State may adopt a fire prevention code and floodplain management regulations within its jurisdiction."
Building Code Council (BCC)
https://www.ncosfm.gov/codes/building-code-council-bcc
Future Code Adoption: 2024 State Building Code (based on 2021 I-Codes) will become effective 12 months after a) code has been published and printed, b) copies have been distributed to state/local officials, c) copies are available to the general public, and d) the residential code council has been instituted pursuant to GS 143-136.1. 2023 legislation prevents future code updates before 2031.
State HBA: North Carolina Home Builders Association
2019 Residential Code of Ohio
Code Language
Model Code Edition: 2018 IECC
Key Amendments: PDF Summary
Effective Date: July 1, 2019
State Mandate: Mandatory statewide
IECC Climate Zones: 4, 5
Local Permission: Chapters 3781. and 3791. of the Revised Code do not prevent the legislative authority of a municipal corporation from making further and additional regulations, not in conflict with those chapters or with the rules the board of building standards adopts.
Ohio Board of Building Standards
https://com.ohio.gov/divisions-and-programs/industrial-compliance/boards/board-of-building-standards
State HBA: Ohio Home Builders Association
2018 International Residential Code with 2022 Oklahoma Amendments, Chapter 11
Code Language
Model Code Edition: 2018 IECC
Key Amendments: PDF Summary
Effective Date: September 14, 2022
State Mandate: Mandatory statewide
IECC Climate Zones: 5, 6
Local Permission: Municipalities and other political subdivisions shall abide by such minimum standards and requirements; provided, nothing in the Oklahoma Uniform Building Code Commission Act shall prevent or take away from such municipalities and other political subdivisions the authority to enact and enforce requirements containing higher standards and requirements than such minimum standards and requirements.
Oklahoma Uniform Building Code Commission
https://oklahoma.gov/oubcc.html
State HBA: Oklahoma Home Builders Association
2023 Oregon Residential Specialty Code (ORSC), Chapter 11
Code Language
Model Code Edition: State-developed code
Effective Date: April 1, 2024
State Mandate: Mandatory statewide
Local Permission: Incentives for municipalities to adopt more stringent energy codes
Residential and Manufactured Structures Board
https://www.oregon.gov/bcd/boards/Pages/rmsb.aspx
Future Code Adoption: The Residential and Manufactured Structures Board has announced the beginning of the code adoption process for the 2026 Oregon Residential Specialty Code (ORSC). Anticipated adoption date: Oct. 1, 2026. Base model codes and standards: 2024 International Residential Code (IRC), Existing Oregon amendments in the 2023 ORSC
State HBA: Oregon Home Builders Association
Uniform Construction Code
Code Language
Model Code Edition: 2018 IECC
Key Amendments: PDF Summary
Effective Date: February 14, 2022
State Mandate: Mandatory statewide
IECC Climate Zones: 5, 6, 4
Local Permission: Municipalities must pass an ordinance adopting the UCC as their municipal building code within 90 days of the publishing of the UCC in order to administer and enforce the UCC themselves. Over 90% of Pennsylvania's 2,562 municipalities have elected to administer and enforce the UCC locally, using their own employees or via certified third party agencies (private code enforcement agencies) that they have retained. In these municipalities, the Department has no code enforcement authority, except where the municipality lacks the services of a person certified as an "Accessibility Inspector/Plans Examiner." If a municipality has "OPTED-OUT," the Department is responsible for all commercial code enforcement in that municipality. The Department also has sole jurisdiction for all elevators and all state-owned buildings, no matter where they are located.
Uniform Construction Code Review and Advisory Council
https://www.pa.gov/agencies/dli/programs-services/labor-management-relations/bureau-of-occupational-and-industrial-safety/uniform-construction-code-home/ucc-review-and-advisory-council
Future Code Adoption: As of July 08, 2025, the triennial Uniform Construction Code update is in process.
State HBA: Pennsylvania Builders Association
Code Language
Model Code Edition: 2018 IECC
Key Amendments: PDF Summary
Effective Date: November 15, 2018
State Mandate: Mandatory statewide
IECC Climate Zones: 1
Local Permission: Not specified that local jurisdictions are allowed to implement their own codes
State HBA: Puerto Rico Builders Association
2009 International Energy Conservation Code (IECC)
Code Language
Model Code Edition: 2009 IECC
Key Amendments: PDF Summary
Effective Date: January 1, 2013
State Mandate: Mandatory statewide
IECC Climate Zones: 3
Local Permission: Local jurisdictions are prohibited from writing or publishing any other building codes in part or in whole. In the absence of Council adoption, local jurisdictions may adopt any or all sections of the administration chapters for all building codes, or may establish administrative procedures for the operation of the local enforcement agency by ordinance. In either instance, however, general administrative provisions adopted by Council, if any, must apply. The Council shall review and may grant local modifications to any of the Codes by the request of a local jurisdiction, for application strictly within that jurisdiction, when it determines that the changes are required to meet local needs due to physical or climatological conditions.
South Carolina Building Codes Council
https://www.llr.sc.gov/bcc/
State HBA: Home Builders Association of South Carolina