Commercial energy code by state: which ASHRAE 90.1 and IECC editions apply in 2026
- Primary data
- Official state code adoption pages, rules and statutes; U.S. DOE BECP State-Level Commercial Codes Energy Use Index
- Data period
- Codes in force on 2026-10-07
- Latest release used
- 2026-09-15
- Next release
- Quarterly re-check (next check January 2027)
- Geography
- United States: 50 states and the District of Columbia
- Sources
- 71 (68 Tier 1)
Checked against official sources on 2026-10-07, the commercial energy code by state splits four ways: 10 states enforce the newest model codes (ASHRAE 90.1-2022 or the 2024 IECC), 15 use 90.1-2019 or the 2021 IECC, 16 jurisdictions use older editions back to 90.1-2004, and 10 states have no statewide commercial code.
Commercial energy code in force by state, October 2026
Checked quarterly. Last checked 2026-10-07. Entries are neutral records of public data; each links to its source record.
| State | Commercial energy code in force, effective date and next change | Date | Evidence | Source |
|---|---|---|---|---|
| Alabama | In force: ASHRAE 90.1-2013 with exceptions (economizers 6.5.1, receptacle control 8.4.2, energy monitoring 8.4.3). Effective: 2016-01-01. Next: Act 2024-443 moved commercial energy code adoption to the Licensing Board for General Contractors; a proposed code was due from its advisory committee by 2025-12-31; no adoption found. Note: DCM table lists 90.1-2013 (dated July 1, 2022 for DCM jurisdiction); DOE gives 2016-01-01 for the statewide commercial code. | 2016-01-01 | both | Record |
| Alaska | In force: No statewide commercial energy code (home rule). Effective: n/a. Next: None found. Note: State plan: Alaska has not adopted a statewide building or energy code; local authorities adopt codes. | n/a | both | Record |
| Arizona | In force: No mandatory statewide commercial energy code (home rule); voluntary IECC 2000 guideline from 2001. Effective: n/a. Next: None found. Note: Local codes are adopted and enforced locally; DOE models population-weighted local codes as 90.1-2019 equivalent. | n/a | both | Record |
| Arkansas | In force: 2014 Arkansas Energy Code: 2009 IECC with ASHRAE 90.1-2007 alternative path. Effective: 2015-01-01. Next: None found. Note: Code text section 112.1 gives effective date 1/1/2015. | 2015-01-01 | both | Record |
| California | In force: 2025 Building Energy Efficiency Standards (Title 24, Part 6), state-specific. Effective: 2026-01-01. Next: None found. Note: State-specific code; mapped to DOE's 90.1-2022 equivalence; applies to permit applications on or after 2026-01-01. | 2026-01-01 | both | Record |
| Colorado | In force: No statewide commercial code enforced by the state (home rule); localities must adopt the Model Low Energy and Carbon Code (2024 IECC based) or stricter when updating any building code after 2026-07-01. Effective: 2023-07-01. Next: Model Low Energy and Carbon Code requirement applies to local code updates after 2026-07-01. Note: State minimum binds only jurisdictions that update codes. | 2023-07-01 | both | Record |
| Connecticut | In force: 2022 Connecticut State Building Code: 2021 IECC (90.1-2019 path). Effective: 2022-10-01. Next: 2026 Connecticut codes awaited approval by the Legislative Regulation Review Committee; the planned 2026-07-01 date was delayed. Note: Applies to permit applications filed from 2022-10-01. | 2022-10-01 | both | Record |
| Delaware | In force: 2024 IECC with amendments; commercial options include ASHRAE 90.1-2022 (7 DE Admin. Code 2101). Effective: 2026-04-11. Next: None found. Note: Secretary's Order 2026-CCE-0002 issued 2026-03-10; previous code 2018 IECC. | 2026-04-11 | both | Record |
| District of Columbia | In force: 2017 DC Energy Conservation Code (2015 IECC / ASHRAE 90.1-2013 base, with DC amendments). Effective: 2020-05-29. Next: DOB construction code rulemaking under way; energy conservation hearing held 2026-09-09. Note: DOE models DC at 90.1-2019 equivalence because of DC amendments. | 2020-05-29 | both | Record |
| Florida | In force: Florida Building Code, 8th Edition (2023), Energy Conservation: 2021 IECC / ASHRAE 90.1-2019 base with Florida amendments. Effective: 2023-12-31. Next: 9th Edition (2026) FBC proposed in rule 61G20-1.001, notice published 2026-10-05. Note: Commission site: FBC 8th Edition effective 2023-12-31. | 2023-12-31 | both | Record |
| Georgia | In force: 2015 IECC with Georgia supplements and amendments (2020, 2022, 2023). Effective: 2020-01-01. Next: None for the energy code: DCA adopted 2024 I-codes effective 2027-01-01, and the energy code is not on that list. | 2020-01-01 | both | Record |
| Hawaii | In force: No statewide code enforced by the state (DOE: home rule); state council adopted the 2018 IECC with amendments in December 2020 and counties enforce it. Effective: 2020-12-15. Next: None found. Note: Counties adopt the state code; page lists 2018 IECC as the currently enforced county code. | 2020-12-15 | both | Record |
| Idaho | In force: 2018 IECC Commercial Provisions with Idaho amendments (IDAPA 24.39.30). Effective: 2021-01-01. Next: None found. | 2021-01-01 | both | Record |
| Illinois | In force: 2024 IECC with Illinois amendments (Illinois Energy Conservation Code, 20 ILCS 3125). Effective: 2025-11-30. Next: None found for the base code. Note: Applies to privately funded commercial facilities. | 2025-11-30 | both | Record |
| Indiana | In force: 2010 Indiana Energy Conservation Code (675 IAC 19-4): ASHRAE 90.1-2007 with amendments. Effective: 2010-05-06. Next: None found. | 2010-05-06 | both | Record |
| Iowa | In force: 2012 IECC Commercial Provisions with Iowa amendments (481 IAC 301.25). Effective: 2014-06-01. Next: None found. Note: Rule re-promulgated under a new agency effective 2025-09-10; edition unchanged. | 2014-06-01 | both | Record |
| Kansas | In force: No state-enforced commercial energy code (home rule); K.S.A. 66-1227 names the 2006 IECC but gives the state no enforcement authority. Effective: n/a. Next: None found. | n/a | both | Record |
| Kentucky | In force: 2012 IECC with Kentucky amendments, via Chapter 13 of the 2018 Kentucky Building Code (815 KAR 7:120). Effective: 2014-10-01. Next: None found. Note: Current regulation version effective 2024-12-03; energy edition unchanged. | 2014-10-01 | both | Record |
| Louisiana | In force: 2021 IECC with Louisiana amendments (LAC 55:VI). Effective: 2023-07-01. Next: Council lists the 2024 ICC codes, including the IECC, for the next cycle with a 2027-01-01 date; final rule not confirmed. | 2023-07-01 | both | Record |
| Maine | In force: 2021 IECC and ASHRAE 90.1-2019 (Maine Uniform Building and Energy Code). Effective: 2025-04-07. Next: None found. Note: Enforcement mandatory in towns of 4,000+ residents. | 2025-04-07 | both | Record |
| Maryland | In force: 2021 IECC with state modifications (COMAR 09.12.51). Effective: 2023-05-29. Next: 2024 IECC proposed in the Maryland Register on 2026-06-26; not final. Note: Localities may make the code stricter, not weaker. | 2023-05-29 | both | Record |
| Massachusetts | In force: Base code: 2021 IECC with Massachusetts amendments (780 CMR Chapter 13); opt-in Stretch and Specialized codes by municipality. Effective: 2024-10-11. Next: None for the base code; Stretch and Specialized code revisions proposed (hearing 2026-06-16). Note: Reader copy saved (mass.gov returned 403 to curl). | 2024-10-11 | both | Record |
| Michigan | In force: 2021 IECC and ASHRAE 90.1-2019 with amendments (Michigan Commercial Energy Code, R 408.31087 ff.). Effective: 2025-04-22. Next: None found. | 2025-04-22 | both | Record |
| Minnesota | In force: ASHRAE 90.1-2019 with Minnesota amendments (2024 Minnesota Commercial Energy Code, Minn. R. ch. 1323). Effective: 2024-01-05. Next: Advisory council recommended reviewing 90.1-2025 instead of adopting 90.1-2022; no effective date. | 2024-01-05 | both | Record |
| Mississippi | In force: No state-enforced commercial energy code (DOE: home rule); Miss. Code 57-39-21 ties commercial buildings to ASHRAE 90.1-2016-based standards with local enforcement only. Effective: n/a. Next: None; the section now sunsets 2029-07-01 after SB 2308 (2026). Note: MDA has no enforcement power under the section. | n/a | both | Record |
| Missouri | In force: No statewide commercial energy code (home rule); state buildings over 5,000 sq ft must meet at least the 2006 IECC or later (RSMo 8.812). Effective: n/a. Next: None found. | n/a | both | Record |
| Montana | In force: 2024 IECC with Montana amendments (ARM Title 24, Chapter 301). Effective: 2026-09-26. Next: None found. Note: DOE September 2026 sheet still lists the 2021 IECC (effective 2022-06-11); state page lists the 2024 edition effective 2026-09-26. | 2026-09-26 | state rule/statute | Record |
| Nebraska | In force: 2018 IECC and ASHRAE 90.1-2016 (Nebraska Energy Code, LB 405). Effective: 2020-07-01. Next: None found. Note: Localities may adopt equivalent local codes. | 2020-07-01 | both | Record |
| Nevada | In force: 2024 IECC adopted by the Governor's Office of Energy (NAC 701.185); localities must follow and may be more stringent. Effective: 2024-08-18. Next: None found. Note: State local-adoption page lists jurisdictions including Clark County and Las Vegas on the 2018 IECC; DOE flags Nevada as home rule and models it at 90.1-2016. | 2024-08-18 | both | Record |
| New Hampshire | In force: 2018 IECC with New Hampshire amendments (state building code, RSA 155-A). Effective: 2022-07-01. Next: None for the energy code: the state building code moved to 2024 I-codes on 2026-07-01 (six-month concurrency), but the energy code listed remains the 2018 IECC. Note: Reader copy saved. | 2022-07-01 | both | Record |
| New Jersey | In force: Energy subcode (N.J.A.C. 5:23-3.18): ASHRAE 90.1-2022 for commercial and other residential; 2024 IECC for low-rise residential. Effective: 2026-08-17. Next: None found. | 2026-08-17 | both | Record |
| New Mexico | In force: 2021 New Mexico Commercial Energy Conservation Code: 2021 IECC with amendments (14.7.9 NMAC). Effective: 2024-01-30. Next: None found. | 2024-01-30 | both | Record |
| New York | In force: 2025 Energy Conservation Construction Code of New York State (2024 IECC and ASHRAE 90.1-2022 based). Effective: 2025-12-31. Next: None found. Note: Transition period approved by the Code Council; reader copy saved. | 2025-12-31 | both | Record |
| North Carolina | In force: 2018 North Carolina Energy Conservation Code (2015 IECC / ASHRAE 90.1-2013 base). Effective: 2019-01-01. Next: 2024 NC Energy Conservation Code (2021 IECC base) adopted but its effective date is postponed until at least one year after conditions in S.L. 2025-2 are met. Note: Page lists the 2018 NC Codes (effective 1/1/2019) as current. | 2019-01-01 | both | Record |
| North Dakota | In force: No state-enforced code (home rule); the State Building Code (2024 IECC with amendments, effective 2026-01-01) binds only jurisdictions that elect to enforce codes. Effective: 2026-01-01. Next: None found. Note: Home rule cities may adopt other codes. | 2026-01-01 | both | Record |
| Ohio | In force: 2024 Ohio Building Code: 2021 I-codes with Ohio amendments (energy: 2021 IECC / ASHRAE 90.1-2019). Effective: 2024-03-01. Next: None found. Note: Energy edition per DOE; state page confirms 2021 I-codes effective 2024-03-01. | 2024-03-01 | both | Record |
| Oklahoma | In force: 2006 IECC and ASHRAE 90.1-2004 (per DOE); state commission is reviewing the commercial 2021 and 2024 IECC. Effective: 2022-09-14. Next: OUBCC Commercial Energy Conservation Technical Committee reviewing the 2021 and 2024 IECC; proposals deadline 2026-07-31. Note: Current edition from DOE; state page confirms only the review. | 2022-09-14 | DOE BECP status | Record |
| Oregon | In force: 2025 Oregon Energy Efficiency Specialty Code, based on ASHRAE 90.1-2022. Effective: 2025-07-01. Next: None found. Note: Effective 2025-01-01 with six-month phase-in; mandatory 2025-07-01. | 2025-07-01 | both | Record |
| Pennsylvania | In force: Uniform Construction Code triennial update: 2021 IECC / ASHRAE 90.1-2019 with amendments. Effective: 2026-01-01. Next: None found. Note: State page confirms IRRC approval 2025-10-16 and effective date 2026-01-01; edition per DOE. | 2026-01-01 | both | Record |
| Rhode Island | In force: RISBC-8 Rhode Island Energy Conservation Code: 2024 IECC with amendments (510-RICR-00-00-8). Effective: 2025-12-01. Next: None found. | 2025-12-01 | both | Record |
| South Carolina | In force: 2009 IECC set by statute as the Energy Standard (S.C. Code 6-10-30). Effective: 2013-01-01. Next: H.5216 (2026) would let the Building Codes Council adopt newer IECC editions; passed the House 2026-04-30, in Senate Judiciary. | 2013-01-01 | both | Record |
| South Dakota | In force: No statewide commercial energy code (home rule); 2009 IECC is a voluntary residential standard (SDCL 11-10-7). Effective: n/a. Next: None found. | n/a | both | Record |
| Tennessee | In force: 2021 IECC with amendments (Rule 0780-02-02-.01): receptacle control, energy monitoring and commissioning removed; 2006 IECC for F and S occupancies. Effective: 2025-04-17. Next: None found. Note: DOE gives effective 2025-08-15; the rule text gives 2025-04-17. | 2025-04-17 | both | Record |
| Texas | In force: 2015 IECC for commercial, industrial and residential buildings over three stories (34 TAC 19.53). Effective: 2016-11-01. Next: None; SECO continues to use the 2015 IECC. | 2016-11-01 | both | Record |
| Utah | In force: 2024 IECC with statewide amendments (Utah Code 15A-2-103, H.B. 65 of 2026). Effective: 2026-07-01. Next: None found. Note: DOE lists adoption 2026-03-01; bill signed 2026-03-17. | 2026-07-01 | both | Record |
| Vermont | In force: 2020 or 2024 Vermont Commercial Building Energy Standards (2018 IECC based; 90.1-2019 alternative path). Effective: 2024-07-01. Next: None found. Note: Rule allowing either the 2020 or 2024 CBES took effect 2026-07-14. | 2024-07-01 | both | Record |
| Virginia | In force: 2021 Uniform Statewide Building Code (2021 IECC with Virginia amendments). Effective: 2024-01-18. Next: 2024 code cycle: DHCD timeline projects 2024 codes effective October 2027 (not adopted). | 2024-01-18 | both | Record |
| Washington | In force: 2021 Washington State Energy Code, Commercial (WAC 51-11C), state-specific amendments of the 2021 IECC. Effective: 2024-03-15. Next: 2024 WSEC-C proposed (CR-102 filed 2026-07-01); proposed effective date 2027-05-03. Note: No ASHRAE 90.1 compliance path; DOE models it as 90.1-2022 equivalent; adoption date not stated (WSR 24-03-085). | 2024-03-15 | both | Record |
| West Virginia | In force: ASHRAE 90.1-2013 for commercial buildings (87 CSR 4, State Building Code). Effective: 2022-08-01. Next: Proposed rule would move to 90.1-2019 and 2024 I-codes; needs legislative approval. Note: State code is enforced only where localities adopt it. | 2022-08-01 | both | Record |
| Wisconsin | In force: 2021 IECC as modified by SPS 361 to 366 (commercial amendments in SPS 363). Effective: 2025-09-01. Next: None found. Note: Register gives effective 2025-09-01; DOE gives 2025-11-01. | 2025-09-01 | both | Record |
| Wyoming | In force: No statewide commercial energy code (home rule); state adopted 2024 IBC, IFC, IMC, IFGC, IEBC but no IECC. Effective: n/a. Next: None found. | n/a | both | Record |
Commercial energy code by state: the 2026 count
Most Americans now live where the commercial code is no more than one edition behind, but a block of 12 jurisdictions remains on codes from 2015 or earlier.
This registry records the commercial energy code by state in force on 2026-10-07 for all 50 states and the District of Columbia. Each entry was read from an official state page, rule or statute and compared with the U.S. Department of Energy (DOE) Building Energy Codes Program spreadsheet dated 2026-09-15 (DOE state portal).
10 states enforce a code built on ASHRAE 90.1-2022 or the 2024 International Energy Conservation Code (IECC). 15 use 90.1-2019 or the 2021 IECC. 16 jurisdictions use 90.1-2016 or older, and 10 states have no statewide commercial code.
0 = 90.1-2022 or 2024 IECC; 3 = 90.1-2019 or 2021 IECC; 6 = 2018 IECC; 9 = 2015 IECC; 12 = 2012 IECC; 15 = 2009 IECC; 18 = 2006 IECC. Blank tile = no statewide commercial code. Checked 2026-10-07
Source: CB&C reading of official state code pages; U.S. DOE Building Energy Codes Program (September 2026)
| Edition (90.1 / IECC equivalent) | Jurisdictions (adopted base code) | Share of U.S. population (%) | Jurisdictions (DOE modeled equivalence) |
|---|---|---|---|
| ASHRAE 90.1-2022 / 2024 IECC | 10 | 28.1 | 8 |
| ASHRAE 90.1-2019 / 2021 IECC | 15 | 35.1 | 15 |
| ASHRAE 90.1-2016 / 2018 IECC | 4 | 1.8 | 8 |
| ASHRAE 90.1-2013 / 2015 IECC | 6 | 18.1 | 9 |
| ASHRAE 90.1-2010 / 2012 IECC | 2 | 2.3 | 3 |
| ASHRAE 90.1-2007 / 2009 IECC | 3 | 4.6 | 7 |
| ASHRAE 90.1-2004 / 2006 IECC | 1 | 1.2 | 1 |
| No statewide commercial code (home rule) | 10 | 8.9 | n/a |
Adopted base code = the model edition the state code is built on, from official state sources. DOE modeled equivalence = DOE map legend (September 2026), which accounts for quantifiable amendments and weights home-rule states by local codes. Population: Census Vintage 2025.
Source: [1][15] U.S. Department of Energy, Building Energy Codes Program (PNNL); U.S. Census Bureau
ASHRAE 90.1 and the IECC: the two model codes states adopt
States do not write commercial energy rules from scratch; they adopt and amend one of two model documents.
ASHRAE Standard 90.1: The energy standard for buildings other than low-rise residential buildings, published by ASHRAE. Approved addenda are combined into a new edition every three years (DOE).
IECC (commercial provisions): The International Energy Conservation Code from the International Code Council, revised every three years. Its commercial chapter lets designers comply through ASHRAE 90.1 instead, so each IECC edition pairs with a 90.1 edition: the 2024 IECC with 90.1-2022, the 2021 IECC with 90.1-2019.
DOE determination: A Federal Register notice in which DOE decides whether a new 90.1 edition saves energy. An affirmative determination starts a two-year clock for states to certify their commercial codes (42 U.S.C. 6833).
Home rule: A state with no mandatory statewide commercial energy code, where cities and counties adopt and enforce their own codes, if any.
| Edition | DOE determination published | State certification deadline | DOE estimated national site energy savings vs prior edition (%) |
|---|---|---|---|
| 90.1-2025 | None as of 2026-10-07 | n/a | n/a |
| 90.1-2022 | 2024-03-06 | 2026-03-06 | 9.8 |
| 90.1-2019 | 2021-07-28 | 2023-07-28 | 4.7 |
| 90.1-2016 | 2018-02-27 | n/a | n/a |
| 90.1-2013 | 2014-09-26 | n/a | n/a |
| 90.1-2010 | 2011-10-19 | n/a | n/a |
| 90.1-2007 | 2011-07-20 | n/a | n/a |
| 90.1-2004 | 2008-12-30 | n/a | n/a |
Certification deadlines are two years after the determination (42 U.S.C. 6833). Deadlines and savings shown only where read on the cited pages.
Source: [4][5][6][9][16] U.S. Department of Energy, Building Energy Codes Program; Federal Register (U.S. Department of Energy); Federal Register (U.S. Department of Energy); U.S. Department of Energy, Building Energy Codes Program; Federal Register API
ASHRAE 90.1-2022 was published in January 2023 (DOE technical support document), and the International Code Council published the 2024 IECC on 2024-08-14 (NAHB). ASHRAE has since published 90.1-2025 (ASHRAE), but without a DOE determination it does not yet set a federal benchmark, so this report measures states against 90.1-2022.
Which states lag behind the current model codes
The median statewide code trails 90.1-2022 by 3 years, but the spread runs to 18 years.
Measured as the gap between the base edition and 90.1-2022, the median statewide code is 3 years behind and the mean is 5.1 years. 12 jurisdictions are two or more editions behind, on 90.1-2013 / the 2015 IECC or older, and they hold 26.2% of U.S. residents.
- Oklahoma: 2006 IECC and 90.1-2004 (DOE), with a state committee now reviewing the 2021 and 2024 IECC commercial provisions.
- Arkansas, Indiana and South Carolina: 90.1-2007 or the 2009 IECC. South Carolina's edition is fixed in statute (S.C. Code 6-10-30).
- Iowa and Kentucky: 2012 IECC.
- Alabama, the District of Columbia, Georgia, North Carolina, Texas and West Virginia: 90.1-2013 or the 2015 IECC.
North Carolina has adopted a 2024 energy code based on the 2021 IECC, but its effective date is postponed until conditions set by the General Assembly are met (NC Office of State Fire Marshal). West Virginia has proposed moving to 90.1-2019, which still needs legislative approval.
50 states and DC; home-rule states have no adopted statewide edition, so DOE assigns them the equivalence of their local codes
Source: CB&C registry of official state sources (2026-10-07); U.S. DOE BECP State-Level Commercial Codes Energy Use Index (2026-09-15)
| State | Adopted base edition | DOE modeled equivalence (September 2026) |
|---|---|---|
| Florida | 90.1-2019 | 90.1-2016 |
| Idaho | 90.1-2016 | 90.1-2013 |
| Iowa | 90.1-2010 | 90.1-2007 |
| Kentucky | 90.1-2010 | 90.1-2007 |
| Louisiana | 90.1-2019 | 90.1-2016 |
| Nebraska | 90.1-2016 | 90.1-2013 |
| Nevada | 90.1-2022 | 90.1-2016 |
| New Hampshire | 90.1-2016 | 90.1-2013 |
| North Carolina | 90.1-2013 | 90.1-2010 |
| Ohio | 90.1-2019 | 90.1-2016 |
| Oregon | 90.1-2022 | 90.1-2019 |
| Tennessee | 90.1-2019 | 90.1-2016 |
DOE rates a state code equivalent to the newest model edition whose Energy Index it does not exceed by more than 1%. Weakening amendments, or local adoption of older codes (Nevada), pull the rating down.
Source: [1][3] U.S. Department of Energy, Building Energy Codes Program (PNNL); U.S. Department of Energy, Building Energy Codes Program
The adopted edition and the efficiency a code delivers can differ. DOE models each state code with its quantifiable amendments and calls it equivalent to the newest edition whose Energy Index it does not exceed by more than 1% (DOE methodology). On that basis DOE places Florida, Ohio, Tennessee and nine other states one edition below their adopted base code, and rates Vermont, Washington and the District of Columbia above theirs.
States with no statewide commercial energy code
10 states leave commercial energy codes to cities and counties, though several have partial state rules.
Alaska, Arizona, Colorado, Hawaii, Kansas, Mississippi, Missouri, North Dakota, South Dakota and Wyoming have no mandatory statewide commercial energy code that the state enforces. On July 1, 2025 they held 30,331,595 people, 8.9% of the U.S. population.
- Colorado: localities that update any building code after 2026-07-01 must adopt the Model Low Energy and Carbon Code, based on the 2024 IECC, or a stricter code.
- Hawaii: the state council adopted the 2018 IECC in December 2020, and the counties enforce it.
- Kansas: K.S.A. 66-1227 names the 2006 IECC but gives the state no authority to enforce it.
- Mississippi: Miss. Code 57-39-21 ties commercial buildings to 90.1-2016-based standards with local enforcement only; a 2026 law extended the section to 2029-07-01.
- North Dakota: the State Building Code, with the 2024 IECC, took effect 2026-01-01 but binds only jurisdictions that choose to enforce codes.
| State | Status on 2026-10-07 | DOE modeled equivalence of local codes | Population, July 1, 2025 |
|---|---|---|---|
| Alaska | No statewide commercial energy code (home rule) | 90.1-2007 | 737,270 |
| Arizona | No mandatory statewide commercial energy code (home rule); voluntary IECC 2000 guideline from 2001 | 90.1-2019 | 7,623,818 |
| Colorado | No statewide commercial code enforced by the state (home rule); localities must adopt the Model Low Energy and Carbon Code (2024 IECC based) or stricter when updating any building code after 2026-07-01 | 90.1-2016 | 6,012,561 |
| Hawaii | No statewide code enforced by the state (DOE: home rule); state council adopted the 2018 IECC with amendments in December 2020 and counties enforce it | 90.1-2016 | 1,432,820 |
| Kansas | No state-enforced commercial energy code (home rule); K.S.A. 66-1227 names the 2006 IECC but gives the state no enforcement authority | 90.1-2010 | 2,977,220 |
| Mississippi | No state-enforced commercial energy code (DOE: home rule); Miss. Code 57-39-21 ties commercial buildings to ASHRAE 90.1-2016-based standards with local enforcement only | 90.1-2010 | 2,954,160 |
| Missouri | No statewide commercial energy code (home rule); state buildings over 5,000 sq ft must meet at least the 2006 IECC or later (RSMo 8.812) | 90.1-2013 | 6,270,541 |
| North Dakota | No state-enforced code (home rule); the State Building Code (2024 IECC with amendments, effective 2026-01-01) binds only jurisdictions that elect to enforce codes | 90.1-2016 | 799,358 |
| South Dakota | No statewide commercial energy code (home rule); 2009 IECC is a voluntary residential standard (SDCL 11-10-7) | 90.1-2007 | 935,094 |
| Wyoming | No statewide commercial energy code (home rule); state adopted 2024 IBC, IFC, IMC, IFGC, IEBC but no IECC | 90.1-2013 | 588,753 |
DOE weights home-rule states by the codes of jurisdictions covering 80% of population or of recent permits.
Source: [1][15][22][23][26][32][37][45][46][55][62][71] U.S. Department of Energy, Building Energy Codes Program (PNNL); U.S. Census Bureau; Alaska Department of Environmental Conservation; Arizona State Senate; Colorado Energy Office; Hawaii State Energy Office; Kansas Office of Revisor of Statutes; Mississippi Legislature; Missouri Revisor of Statutes; North Dakota Department of Commerce; South Dakota Legislature; Wyoming State Fire Marshal
How many people each code edition covers
Population weighting changes the picture: a few large states on new codes move the national share more than many small states.
Weighting each state by its Census Vintage 2025 population, 35.1% of U.S. residents live in jurisdictions on 90.1-2019 or the 2021 IECC and 28.1% on 90.1-2022 or the 2024 IECC. The 90.1-2013 / 2015 IECC group holds 18.1%, mostly because of Texas.
Percent of the July 1, 2025 population of the 50 states and DC, by the state's adopted base edition
Source: CB&C calculation from official state code sources and U.S. Census Bureau Vintage 2025 state population estimates
Population is a proxy for where commercial construction happens, not a measure of it. For permit volumes see the commercial building permits guide, and for the age of the existing stock see how old U.S. commercial buildings are.
What changed in 2025 and 2026
11 states moved to a new commercial code between July 2025 and October 2026; 14 more have the next code proposed, delayed or under review.
| State | Code now in force | Effective | Code listed by DOE in June 2025 |
|---|---|---|---|
| Oregon | 2025 Oregon Energy Efficiency Specialty Code, based on ASHRAE 90.1-2022 | 2025-07-01 | 90.1-2019 |
| Wisconsin | 2021 IECC as modified by SPS 361 to 366 (commercial amendments in SPS 363) | 2025-09-01 | 2015 IECC and 90.1-2013^ |
| Illinois | 2024 IECC with Illinois amendments (Illinois Energy Conservation Code, 20 ILCS 3125) | 2025-11-30 | 2021 IECC and 90.1-2019 |
| Rhode Island | RISBC-8 Rhode Island Energy Conservation Code: 2024 IECC with amendments (510-RICR-00-00-8) | 2025-12-01 | 2024 IECC |
| New York | 2025 Energy Conservation Construction Code of New York State (2024 IECC and ASHRAE 90.1-2022 based) | 2025-12-31 | 2018 IECC and 90.1-2016^ |
| California | 2025 Building Energy Efficiency Standards (Title 24, Part 6), state-specific | 2026-01-01 | 2022 Building Energy Efficiency Standards |
| Pennsylvania | Uniform Construction Code triennial update: 2021 IECC / ASHRAE 90.1-2019 with amendments | 2026-01-01 | 2018 IECC and 90.1-2016 |
| Delaware | 2024 IECC with amendments; commercial options include ASHRAE 90.1-2022 (7 DE Admin. Code 2101) | 2026-04-11 | 2018 IECC and 90.1-2016 |
| Utah | 2024 IECC with statewide amendments (Utah Code 15A-2-103, H.B. 65 of 2026) | 2026-07-01 | 2021-IECC and 90.1-2019^ |
| New Jersey | Energy subcode (N.J.A.C. 5:23-3.18): ASHRAE 90.1-2022 for commercial and other residential; 2024 IECC for low-rise residential | 2026-08-17 | 90.1-2019^ |
| Montana | 2024 IECC with Montana amendments (ARM Title 24, Chapter 301) | 2026-09-26 | 2021 IECC and 90.1-2019 |
Oregon's 2025 code took effect 2025-01-01 with a phase-in and became mandatory 2025-07-01; the date shown is the mandatory date.
Source: [1][58][70][34][60][53][25][59][28][65][51][47] U.S. Department of Energy, Building Energy Codes Program (PNNL); Oregon Building Codes Division; Wisconsin Legislative Reference Bureau; Illinois Capital Development Board; Rhode Island Secretary of State; New York Department of State; California Energy Commission; Pennsylvania Department of Labor and Industry; Delaware Register of Regulations (DNREC); Utah Legislature; New Jersey Department of Community Affairs; Montana Department of Labor and Industry, Building Codes Program
Some new codes stalled. Connecticut's 2026 codes, expected on 2026-07-01, await approval by a legislative committee. New Hampshire moved its building code to the 2024 I-codes on 2026-07-01 but kept the 2018 IECC as its energy code. Minnesota's advisory council recommended reviewing 90.1-2025 instead of adopting 90.1-2022.
| State | Status of the next code |
|---|---|
| Alabama | Act 2024-443 moved commercial energy code adoption to the Licensing Board for General Contractors; a proposed code was due from its advisory committee by 2025-12-31; no adoption found |
| Colorado | Model Low Energy and Carbon Code requirement applies to local code updates after 2026-07-01 |
| Connecticut | 2026 Connecticut codes awaited approval by the Legislative Regulation Review Committee; the planned 2026-07-01 date was delayed |
| District of Columbia | DOB construction code rulemaking under way; energy conservation hearing held 2026-09-09 |
| Florida | 9th Edition (2026) FBC proposed in rule 61G20-1.001, notice published 2026-10-05 |
| Louisiana | Council lists the 2024 ICC codes, including the IECC, for the next cycle with a 2027-01-01 date; final rule not confirmed |
| Maryland | 2024 IECC proposed in the Maryland Register on 2026-06-26; not final |
| Minnesota | Advisory council recommended reviewing 90.1-2025 instead of adopting 90.1-2022; no effective date |
| North Carolina | 2024 NC Energy Conservation Code (2021 IECC base) adopted but its effective date is postponed until at least one year after conditions in S.L. 2025-2 are met |
| Oklahoma | OUBCC Commercial Energy Conservation Technical Committee reviewing the 2021 and 2024 IECC; proposals deadline 2026-07-31 |
| South Carolina | H.5216 (2026) would let the Building Codes Council adopt newer IECC editions; passed the House 2026-04-30, in Senate Judiciary |
| Virginia | 2024 code cycle: DHCD timeline projects 2024 codes effective October 2027 (not adopted) |
| Washington | 2024 WSEC-C proposed (CR-102 filed 2026-07-01); proposed effective date 2027-05-03 |
| West Virginia | Proposed rule would move to 90.1-2019 and 2024 I-codes; needs legislative approval |
Includes proposals and codes adopted with a delayed or conditional date. None of these changes is in force on 2026-10-07.
Source: [21][26][27][29][30][39][41][44][54][57][61][67][68][69] Alabama Division of Construction Management; Colorado Energy Office; Connecticut Department of Administrative Services, Office of the State Building Inspector; DC Department of Buildings; Florida Building Commission / Florida Administrative Register; Louisiana State Uniform Construction Code Council; Maryland Division of State Documents; Minnesota Department of Labor and Industry; North Carolina Office of State Fire Marshal; Oklahoma Uniform Building Code Commission; South Carolina Legislature; Virginia Department of Housing and Community Development; Washington State Building Code Council; West Virginia Secretary of State
Licensing and permitting rules also differ by state; see the commercial contractor licensing registry.
Counts and distributions
Count of jurisdictions by adopted base edition
Formulacount(states with base edition = X), 50 states + DC
Inputs: per-state rows in fact_sheet.csv (DOE listing, official source); derived d1, d3, d5, d7, d9, d11, d13, d15 (fact sheet rows)
Result: 10 on 90.1-2022; 15 on 90.1-2019; 4 on 90.1-2016; 6 on 90.1-2013; 2 on 90.1-2010; 3 on 90.1-2007; 1 on 90.1-2004; 10 with no statewide code
25 of the 41 statewide-code jurisdictions are on the 2019 or 2022 generation of codes.
Limitations: Base edition before amendments. California's state-specific code is mapped to DOE's 90.1-2022 equivalence; Washington's to its 2021 IECC base.
Years behind 90.1-2022
Formula2022 minus base edition year, statewide-code jurisdictions only
Inputs: derived d17, d18 (fact sheet rows)
Result: median 3 years, mean 5.1 years
The typical state is one edition behind; the long tail of old codes raises the mean.
Limitations: Edition gap, not elapsed time since publication; home-rule states excluded.
Population share by edition
Formulasum(state population in group) / population of 50 states + DC x 100
Inputs: Census rows per state; derived d2, d4, d16, d32 (fact sheet rows)
Result: 28.1% on 90.1-2022; 35.1% on 90.1-2019; 63.2% on 90.1-2019 or newer; 8.9% in home-rule states
About two in three residents live in a state whose code is at most one edition old.
Limitations: Many home-rule residents live in cities with local codes; population is not construction volume.
Amendment gap
Formulacount(DOE modeled edition < adopted base edition)
Inputs: DOE legend and official rows per state; derived d21 (fact sheet rows)
Result: 12 states
Adopting a new edition does not guarantee its full efficiency; amendments and local adoption matter.
Limitations: DOE captures only amendments it can model with prototype buildings; Montana excluded because DOE still lists its older code.
Key findings
- 10 states had a commercial code based on 90.1-2022 or the 2024 IECC on 2026-10-07: California, Delaware, Illinois, Montana, Nevada, New Jersey, New York, Oregon, Rhode Island and Utah.[1][47][51]
- 15 states used 90.1-2019 or the 2021 IECC on 2026-10-07, the largest group, covering 35.1% of U.S. residents.[1][15]
- 28.1% of the U.S. population lived in states on 90.1-2022 or the 2024 IECC in October 2026, led by California and New York.[15][25][53]
- Oklahoma's commercial code is based on the 2006 IECC and 90.1-2004, the oldest in the U.S. in October 2026, 18 years behind 90.1-2022.[1][57]
- 12 jurisdictions enforce 90.1-2013 / the 2015 IECC or older, covering 26.2% of the U.S. population in 2025.[1][15]
- Texas has used the 2015 IECC for commercial buildings since 2016-11-01, and its energy office says it continues to do so.[64]
- 10 states had no statewide commercial energy code in October 2026: Alaska, Arizona, Colorado, Hawaii, Kansas, Mississippi, Missouri, North Dakota, South Dakota and Wyoming.[1]
- The 10 home-rule states held 30,331,595 residents (8.9% of the U.S.) on July 1, 2025.[15]
- DOE's September 2026 status data rates 8 jurisdictions as equivalent to 90.1-2022, compared with 10 that have adopted it, because amendments and local adoption lower some states' modeled efficiency.[1][3]
- DOE models 12 states, including Florida, Ohio and Oregon, at least one edition below the base edition they adopted (September 2026).[1]
- DOE estimated that 90.1-2022 saves 9.8% of site energy, 9.4% of source energy and 8.9% of energy cost compared with 90.1-2019 (national average, 2024 determination).[4]
- Federal law gave states until 2026-03-06, two years after DOE's 90.1-2022 determination, to certify that their commercial codes meet or exceed it.[5][8]
- ASHRAE has published 90.1-2025, which incorporates 105 addenda, but no DOE determination on it appeared in the Federal Register as of 2026-10-07.[12][16]
- 11 states put a new commercial energy code into force between July 2025 and October 2026.[1][65][28]
Executive summary
- 10 states enforce a commercial energy code built on ASHRAE 90.1-2022 or the 2024 IECC, the newest editions with a DOE determination, covering 28.1% of the U.S. population (Census Vintage 2025).
- 15 states use 90.1-2019 or the 2021 IECC. Together, 25 jurisdictions on 90.1-2019 or newer hold 63.2% of U.S. residents.
- 12 jurisdictions, home to 26.2% of the population, enforce 90.1-2013 / the 2015 IECC or older. Texas, North Carolina and Georgia are the largest.
- 10 states have no statewide commercial energy code; 30,331,595 people lived in them on July 1, 2025.
- The median statewide code trails 90.1-2022 by 3 years (one edition); the mean gap is 5.1 years.
- DOE models 12 states at least one edition below the code they adopted, because of weakening amendments or older local codes.
- 11 states put a new commercial code into force between July 2025 and October 2026, and 14 more have a newer code proposed, delayed or under review.
Questions people ask
What energy code does my state use?
Find your state in the registry table on this page: each row gives the commercial code in force on 2026-10-07, its effective date and a link to the official source. In home-rule states the answer depends on the city or county, so check with the local building department.
What is ASHRAE 90.1?
ASHRAE Standard 90.1 is the model energy standard for commercial buildings and multifamily buildings of four or more stories. ASHRAE combines approved addenda into a new edition every three years; the newest with a DOE determination is 90.1-2022, published in January 2023.
Which states have adopted IECC 2021?
In October 2026, 15 states use the 2021 IECC or its partner standard 90.1-2019 for commercial buildings: Connecticut, Florida, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota (90.1-2019), New Mexico, Ohio, Pennsylvania, Tennessee, Virginia, Washington and Wisconsin.
Do all states have an energy code?
No. 10 states have no mandatory statewide commercial energy code: Alaska, Arizona, Colorado, Hawaii, Kansas, Mississippi, Missouri, North Dakota, South Dakota and Wyoming. Cities in those states often adopt their own codes.
How often are energy codes updated?
Both model codes run on three-year cycles. Federal law then gives DOE 12 months to issue a determination on a new 90.1 edition, and states two years after that to certify their codes. Actual state adoption is slower: the median statewide code in October 2026 was one edition behind.
Frequently asked questions
How many states use the newest commercial energy code?
10 states had a commercial code based on 90.1-2022 or the 2024 IECC on 2026-10-07.
Which state has the oldest commercial energy code?
Oklahoma, whose code is based on the 2006 IECC and 90.1-2004 according to DOE's September 2026 data, 18 years behind 90.1-2022.
What share of Americans live under the newest commercial code?
28.1% of the U.S. population lived in states on 90.1-2022 or the 2024 IECC, based on Census Vintage 2025 estimates.
What energy code does Texas use for commercial buildings?
Texas uses the 2015 IECC for commercial, industrial and residential buildings over three stories, effective since 2016-11-01.
What energy code does California use?
California uses its own 2025 Building Energy Efficiency Standards (Title 24, Part 6) for permit applications on or after 2026-01-01; DOE rates it equivalent to 90.1-2022.
What energy code does Florida use for commercial buildings?
The Florida Building Code, 8th Edition (2023), Energy Conservation, based on the 2021 IECC and 90.1-2019, effective 2023-12-31. A 9th Edition (2026) has been proposed.
How much energy does 90.1-2022 save?
DOE estimated national savings of 9.8% of site energy and 8.9% of energy cost compared with 90.1-2019 in its 2024 determination.
Has DOE issued a determination on ASHRAE 90.1-2025?
No determination on 90.1-2025 appeared in the Federal Register as of 2026-10-07, so 90.1-2022 remains the latest edition states must certify against.
When were states required to certify against 90.1-2022?
By 2026-03-06, two years after DOE published its determination on 2024-03-06.
How many states changed their commercial energy code recently?
11 states put a new commercial energy code into force between July 2025 and October 2026, and 14 more have a newer code proposed, delayed or under review.
Download the data
Every table in this report is available as a CSV under CC BY 4.0. The fact sheet lists each value with its source URL and access date.
- derived_metrics.csv (CSV)
- fact_sheet.csv (CSV)
- Commercial energy code in force by state, October 2026 (CSV)
- Commercial energy code editions in force, 50 states and DC, October 2026 (CSV)
- New commercial energy codes effective from July 2025 to October 2026 (CSV)
- States where DOE models the code below its base edition (CSV)
- States with no statewide commercial energy code (home rule) (CSV)
- ASHRAE Standard 90.1 editions, DOE determinations and state deadlines (CSV)
- Pending or proposed commercial energy code changes, October 2026 (CSV)
For journalists and researchers
If you cite only a few, cite these
- 10 states enforced a commercial energy code based on ASHRAE 90.1-2022 or the 2024 IECC in October 2026.[1]
- 63.2% of U.S. residents lived in states whose commercial energy code was 90.1-2019 / 2021 IECC or newer in October 2026.[15]
- 10 states, home to 30,331,595 people in 2025, had no statewide commercial energy code in October 2026.[1][15]
Most quotable statistics
- 10 states enforced a commercial energy code based on ASHRAE 90.1-2022 or the 2024 IECC in October 2026.[1]
- 63.2% of U.S. residents lived in states whose commercial energy code was 90.1-2019 / 2021 IECC or newer in October 2026.[15]
- 10 states, home to 30,331,595 people in 2025, had no statewide commercial energy code in October 2026.[1][15]
- 12 U.S. jurisdictions enforced commercial energy codes based on 2015 or older model codes in October 2026.[1]
- DOE modeled 12 states below the commercial code edition they adopted (September 2026).[1]
- 11 states put a new commercial energy code into force between July 2025 and October 2026.[1]
Press summary
A state-by-state check of commercial building energy codes by Commercial Builders & Contractors finds that 10 states enforced a code based on ASHRAE 90.1-2022 or the 2024 IECC on 2026-10-07, and 15 more used the 2019 generation. Weighted by Census Vintage 2025 population, 63.2% of U.S. residents live in states on 90.1-2019 or newer. 12 jurisdictions, home to 26.2% of the population, remain on 2015 or older model codes, with Oklahoma oldest on 90.1-2004. 10 states have no statewide commercial code. DOE's September 2026 status data rates 12 states at least one edition below the code they adopted, because of amendments or older local codes. 11 states moved to a new code between July 2025 and October 2026, including Montana, New Jersey and Utah. Each state entry links to its official source. The registry is checked quarterly; readers should confirm the code for any project with the local building department.
Suggested headlines
- 10 states now enforce the newest commercial energy code
- 10 states still have no statewide commercial energy code
- Oklahoma's commercial energy code trails the model code by 18 years
- DOE rates 12 states below the energy code they adopted
- 11 states switched commercial energy codes in the past 15 months
How to cite this report
Commercial Builders & Contractors. (2026). Commercial energy code by state: which ASHRAE 90.1 and IECC editions apply in 2026. Retrieved from https://commercialbuildersandcontractors.com/commercial-energy-code-by-state/
Reuse license
Data and tables are licensed CC BY 4.0. Attribution: “Source: Commercial Builders & Contractors, Commercial energy code by state: which ASHRAE 90.1 and IECC editions apply in 2026” with a link to this page.
Methodology
Selection: the registry covers the 50 states and the District of Columbia. For each, the commercial energy code in force on 2026-10-07 was read from an official source: a state agency code page, administrative rule, register notice or statute. Unmodified copies are saved in raw/states. The U.S. DOE Building Energy Codes Program spreadsheet dated 2026-09-15 supplied a second record for every state and the modeled equivalence ratings.
Evidence levels: 'both' means the state source and DOE agree on the edition; 'state rule/statute' means the state source is newer than DOE (Montana); 'DOE BECP status' means the state page did not state the edition and DOE's record was used (Oklahoma). Every state was verified at one of these levels, so none is excluded from the counts.
Classification: each statewide code is assigned the ASHRAE 90.1 edition its base model code pairs with (2024 IECC = 90.1-2022, 2021 IECC = 90.1-2019, and so on). California's state-specific Title 24 is mapped to DOE's 90.1-2022 equivalence. Washington's state code is mapped to its 2021 IECC base. Vermont is mapped to its 2018 IECC base. States DOE designates as home rule are counted as having no statewide commercial code, even where a statute names an edition without state enforcement.
Conflicts: where the state source and DOE differ, the state source wins and the difference is noted in the registry (for example Montana's 2026 adoption, and effective dates in Tennessee and Wisconsin). Pending codes are counted only when in force.
Derived metrics: edition counts, years behind 90.1-2022, population shares and the amendment gap are computed in scripts/build.py from fact_sheet.csv; formulas and input rows are in derived_metrics.csv. Population is the Census Bureau's Vintage 2025 estimate for July 1, 2025.
Limitations: local governments can adopt stricter codes; transition periods let some projects use the previous code; DOE equivalence captures only amendments it can model; population is not a measure of construction volume. Last updated 2026-10-08.
This report presents published data with its limitations. It is not legal, financial or investment advice.
Sources, ranked by quality
Tier 1: primary and official sources (68)
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- [2] U.S. Department of Energy, Building Energy Codes Program. State Portal: Status of State Energy Code Adoption. September 2026. Accessed 2026-10-07.
- [3] U.S. Department of Energy, Building Energy Codes Program. State Energy Code Methodology. Current methodology. Accessed 2026-10-07.
- [4] U.S. Department of Energy, Building Energy Codes Program. Model Energy Code Determinations. Determinations through December 2024. Accessed 2026-10-07.
- [5] Federal Register (U.S. Department of Energy). Determination Regarding Energy Efficiency Improvements in ANSI/ASHRAE/IES Standard 90.1-2022 (FR Doc. 2024-04717). Published 2024-03-06. Accessed 2026-10-07.
- [6] Federal Register (U.S. Department of Energy). Final Determination Regarding Energy Efficiency Improvements in ANSI/ASHRAE/IES Standard 90.1-2019 (FR Doc. 2021-15971). Published 2021-07-28. Accessed 2026-10-07.
- [7] U.S. Department of Energy, Building Energy Codes Program. State Energy Code Certifications. Deadlines current to 2026. Accessed 2026-10-07.
- [8] Legal Information Institute, Cornell Law School (U.S. Code text). 42 U.S. Code 6833, Updating State building energy efficiency codes. Statute in force. Accessed 2026-10-07.
- [9] U.S. Department of Energy, Building Energy Codes Program. Previous Determinations. 1999 to 2021 determinations. Accessed 2026-10-07.
- [10] U.S. Department of Energy / Pacific Northwest National Laboratory. Standard 90.1-2022 Final Determination Technical Support Document. February 2024. Accessed 2026-10-07.
- [11] U.S. Department of Energy, Building Energy Codes Program. Commercial and Residential Building Energy Codes. Undated program page. Accessed 2026-10-07.
- [12] ASHRAE. Standard 90.1 (bookstore page, 2025 edition). 2025 edition. Accessed 2026-10-07.
- [13] ASHRAE. ASHRAE Strengthens Standard 90.1 Foundation with Renewed Emphasis on Commercial Building Energy Efficiency. 2026-07-16. Accessed 2026-10-07.
- [14] Federal Register (U.S. Department of Energy). Updating and Improving the Methodology for Assessing Affordability and Cost-Effectiveness of Building Energy Codes (FR Doc. 2026-08646). Published 2026-05-04. Accessed 2026-10-07.
- [15] U.S. Census Bureau. Annual Estimates of the Resident Population for the States (NST-EST2025-ALLDATA, Vintage 2025). July 1, 2025; file posted 2026-01-27. Accessed 2026-10-07.
- [16] Federal Register API. Federal Register document search: "90.1-2025". Searched 2026-10-07. Accessed 2026-10-07.
- [17] U.S. Department of Energy, Building Energy Codes Program (Tableau Public). BECP Status of State Energy Code Adoption (dashboard). Last published 2026-09-29. Accessed 2026-10-07.
- [21] Alabama Division of Construction Management. State Building Code adopted codes (Alabama). Code in force on 2026-10-07. Accessed 2026-10-07.
- [22] Alaska Department of Environmental Conservation. State of Alaska Comprehensive Sustainable Energy Action Plan (Alaska). Code in force on 2026-10-07. Accessed 2026-10-07.
- [23] Arizona State Senate. Fact sheet for S.B. 1321 (51st Legislature) (Arizona). Code in force on 2026-10-07. Accessed 2026-10-07.
- [24] Arkansas Energy Office. Building energy codes (Arkansas). Code in force on 2026-10-07. Accessed 2026-10-07.
- [25] California Energy Commission. 2025 Building Energy Efficiency Standards (California). Code in force on 2026-10-07. Accessed 2026-10-07.
- [26] Colorado Energy Office. Building Energy Codes Toolkit (Colorado). Code in force on 2026-10-07. Accessed 2026-10-07.
- [27] Connecticut Department of Administrative Services, Office of the State Building Inspector. Connecticut State Building Code regulations (Connecticut). Code in force on 2026-10-07. Accessed 2026-10-07.
- [28] Delaware Register of Regulations (DNREC). 29 DE Reg. 875: Final regulation, State Energy Conservation Code (Delaware). Code in force on 2026-10-07. Accessed 2026-10-07.
- [29] DC Department of Buildings. DC Construction Codes (District of Columbia). Code in force on 2026-10-07. Accessed 2026-10-07.
- [30] Florida Building Commission / Florida Administrative Register. Rule 61G20-1.001 notice and Florida Building Commission home page (Florida). Code in force on 2026-10-07. Accessed 2026-10-07.
- [31] Georgia Department of Community Affairs. Current State Minimum Standard Codes for Construction (Georgia). Code in force on 2026-10-07. Accessed 2026-10-07.
- [32] Hawaii State Energy Office. Hawaii Building Energy Codes (Hawaii). Code in force on 2026-10-07. Accessed 2026-10-07.
- [33] Idaho Division of Occupational and Professional Licenses. IDAPA 24.39.30, Rules of Building Safety (Idaho). Code in force on 2026-10-07. Accessed 2026-10-07.
- [34] Illinois Capital Development Board. Illinois Energy Conservation Code (Illinois). Code in force on 2026-10-07. Accessed 2026-10-07.
- [35] Indiana Department of Homeland Security. Fire Prevention and Building Safety Commission rules (Indiana). Code in force on 2026-10-07. Accessed 2026-10-07.
- [36] Iowa Legislature. Iowa Administrative Code 481, chapter 301 (Iowa). Code in force on 2026-10-07. Accessed 2026-10-07.
- [37] Kansas Office of Revisor of Statutes. K.S.A. 66-1227 (Kansas). Code in force on 2026-10-07. Accessed 2026-10-07.
- [38] Kentucky Department of Housing, Buildings and Construction. 2018 Kentucky Building Code, 4th edition (Kentucky). Code in force on 2026-10-07. Accessed 2026-10-07.
- [39] Louisiana State Uniform Construction Code Council. Louisiana Construction Code Information (Louisiana). Code in force on 2026-10-07. Accessed 2026-10-07.
- [40] Maine Governor's Energy Office. Building codes (Maine). Code in force on 2026-10-07. Accessed 2026-10-07.
- [41] Maryland Division of State Documents. COMAR 09.12.51.04 (Maryland). Code in force on 2026-10-07. Accessed 2026-10-07.
- [42] Commonwealth of Massachusetts. Massachusetts building energy codes (Massachusetts). Code in force on 2026-10-07. Accessed 2026-10-07.
- [43] Michigan Office of Administrative Hearings and Rules. Michigan Administrative Code R 408.31087 to 408.31099 (Michigan). Code in force on 2026-10-07. Accessed 2026-10-07.
- [44] Minnesota Department of Labor and Industry. 2024 Minnesota Commercial Energy Code fact sheet (Minnesota). Code in force on 2026-10-07. Accessed 2026-10-07.
- [45] Mississippi Legislature. SB 2308 (2026 Regular Session) (Mississippi). Code in force on 2026-10-07. Accessed 2026-10-07.
- [46] Missouri Revisor of Statutes. RSMo 8.812 (Missouri). Code in force on 2026-10-07. Accessed 2026-10-07.
- [47] Montana Department of Labor and Industry, Building Codes Program. Current Codes (Montana). Code in force on 2026-10-07. Accessed 2026-10-07.
- [48] Nebraska Department of Water, Energy, and Environment. Energy Codes (Nebraska). Code in force on 2026-10-07. Accessed 2026-10-07.
- [49] Nevada Governor's Office of Energy. Building Energy Codes: State Adoption Status (Nevada). Code in force on 2026-10-07. Accessed 2026-10-07.
- [50] New Hampshire State Fire Marshal. State Building Code (New Hampshire). Code in force on 2026-10-07. Accessed 2026-10-07.
- [51] New Jersey Department of Community Affairs. Current Code Adoptions (New Jersey). Code in force on 2026-10-07. Accessed 2026-10-07.
- [52] New Mexico State Records Center and Archives. 14.7.9 NMAC, 2021 New Mexico Commercial Energy Conservation Code (New Mexico). Code in force on 2026-10-07. Accessed 2026-10-07.
- [53] New York Department of State. Notice of adoption, 2025 Energy Code (New York). Code in force on 2026-10-07. Accessed 2026-10-07.
- [54] North Carolina Office of State Fire Marshal. Codes: Current and Past (North Carolina). Code in force on 2026-10-07. Accessed 2026-10-07.
- [55] North Dakota Department of Commerce. Building Codes (North Dakota). Code in force on 2026-10-07. Accessed 2026-10-07.
- [56] Ohio Board of Building Standards. 2024 Ohio Building, Mechanical and Plumbing Code Rules (Ohio). Code in force on 2026-10-07. Accessed 2026-10-07.
- [57] Oklahoma Uniform Building Code Commission. Oklahoma Uniform Building Code Commission (Oklahoma). Code in force on 2026-10-07. Accessed 2026-10-07.
- [58] Oregon Building Codes Division. Oregon Energy Efficiency Specialty Code (Oregon). Code in force on 2026-10-07. Accessed 2026-10-07.
- [59] Pennsylvania Department of Labor and Industry. Uniform Construction Code (UCC) (Pennsylvania). Code in force on 2026-10-07. Accessed 2026-10-07.
- [60] Rhode Island Secretary of State. 510-RICR-00-00-8 (Rhode Island). Code in force on 2026-10-07. Accessed 2026-10-07.
- [61] South Carolina Legislature. S.C. Code Title 6 Chapter 10 (South Carolina). Code in force on 2026-10-07. Accessed 2026-10-07.
- [62] South Dakota Legislature. SDCL Chapter 11-10 (South Dakota). Code in force on 2026-10-07. Accessed 2026-10-07.
- [63] Tennessee Secretary of State. Rule chapter 0780-02-02 (Tennessee). Code in force on 2026-10-07. Accessed 2026-10-07.
- [64] Texas Comptroller, State Energy Conservation Office. Commercial energy code (Texas). Code in force on 2026-10-07. Accessed 2026-10-07.
- [65] Utah Legislature. H.B. 65 (2026), enrolled (Utah). Code in force on 2026-10-07. Accessed 2026-10-07.
- [66] Vermont Department of Public Service. Commercial Building Energy Standards (Vermont). Code in force on 2026-10-07. Accessed 2026-10-07.
- [67] Virginia Department of Housing and Community Development. Building and fire codes (Virginia). Code in force on 2026-10-07. Accessed 2026-10-07.
- [68] Washington State Building Code Council. 2021 Washington State Energy Code, Commercial, 2nd edition (Washington). Code in force on 2026-10-07. Accessed 2026-10-07.
- [69] West Virginia Secretary of State. 87 CSR 4, State Building Code (West Virginia). Code in force on 2026-10-07. Accessed 2026-10-07.
- [70] Wisconsin Legislative Reference Bureau. Wis. Admin. Code SPS 363 (Wisconsin). Code in force on 2026-10-07. Accessed 2026-10-07.
- [71] Wyoming State Fire Marshal. Electrical safety updates (2024 International Codes adoption) (Wyoming). Code in force on 2026-10-07. Accessed 2026-10-07.
Tier 2: trade bodies, market research, company data (2)
- [18] National Association of Home Builders. 2024 International Energy Conservation Code. Undated. Accessed 2026-10-07.
- [19] National Association of Home Builders. Energy Code Adoption by State. Undated. Accessed 2026-10-07.
Tier 3: journalism and expert commentary (1)
- [20] Health Facilities Management (American Hospital Association). ASHRAE Standard 90.1 introduces new energy-saving requirement. 2026-04-24. Accessed 2026-10-07.