Codes of Record

International Energy Conservation Code, residential

Colorado: 2024 IECC residential, local option

The 2024 International Energy Conservation Code (IECC) for residential buildings has been in force in Colorado since Jul 1, 2026. It applies by local option. Adopted by Colorado Energy Code Board (published by the Colorado Energy Office); counties and municipalities adopt it. The legal citation is C.R.S. 24-38.5-401; C.R.S. 30-28-211(3.5); C.R.S. 31-15-602(3.5).

Record of adoption

Edition in force

2024 IECC

Colorado Model Low Energy and Carbon Code

Partial

In force since
Legal citation
C.R.S. 24-38.5-401; C.R.S. 30-28-211(3.5); C.R.S. 31-15-602(3.5)
Adopted by
Colorado Energy Code Board (published by the Colorado Energy Office); counties and municipalities adopt it
Second reading
Applies
Local option
State amendments
Major
Also called
MLECC, Model Low Energy and Carbon Code V2

Jul 1, 2026, is the trigger date for local governments; Exhibit A lists V2 as effective Mar 30, 2026.

Exceptions

  • No locality has to adopt any building code; the model code (or an equal or better one) is required only when a county or municipality updates its other building codes after July 1, 2026
  • State buildings follow the 2024 IECC under the State Buildings Program
  • HB25-1269 says adopting a wildfire resiliency code does not by itself require an energy code

How Colorado adopts the IECC residential

  • More than one path
  • The legislature names the edition in statute
  • The legislature sets the update schedule
  • A recent law changed the process

The legislature (HB22-1362) created the Energy Code Board and required a model code based on the 2024 IECC, then required local governments that update any building code on or after Jul 1, 2026, to adopt it or something better. Locals adopt by their own ordinance or resolution; HB25-1269 later exempted wildfire-code adopters from the energy code duty.

Cycle. Set by statute: model code by 2025, local trigger Jul 1, 2026; the Energy Office recommends a 3-year local cycle.

Laws, rulings, and other actions

  1. Legislation
    HB22-1362 Building Greenhouse Gas Emissions2022 regular session

    Created the Energy Code Board, required a model low energy and carbon code based on the 2024 IECC, and requires local governments updating building codes on or after Jul 1, 2026, to adopt an energy code at least as good.

    Enacted 2022, local trigger date Jul 1, 2026

    content.leg.colorado.gov (opens in a new tab)
  2. Other action
    Energy Code Board published the Colorado Model Low Energy and Carbon Code (press release dated Sep 2, 2025; page also shows Aug 28, 2025)

    Published the model code based on a modified 2024 IECC, to become the local minimum on Jul 1, 2026.

  3. Legislation
    HB25-1269 Building Decarbonization Measures2025 regular session

    Clarifies that a local government is not required to adopt an energy code solely because it adopted a wildfire resiliency code.

    Enacted May 20, 2025 (Governor Signed, Chapter 216)

    leg.colorado.gov (opens in a new tab)

How it was checked

Partial

Researched in the state’s own record. The seal stays broken until the passage is on file word for word.

Read twice: a second, blind reading of the state’s record agreed with the first on .

The state’s record was last read on , from six source pages.

Evidence 7 sources

Sources for the record itself come first, the state’s own records ahead of others. A label marks a source about something else, such as an exception. A source marked secondary is not the state’s own record.

  • “The 2024 edition of the International Energy Conservation Code (IECC)”

    Approved State Building Codes, Exhibit A (Rev. 10/2026)Colorado Office of the State Architectosa.colorado.gov (opens in a new tab)Agency pageRetrieved

  • “adopt and enforce the Colorado Model Low Energy and Carbon Code upon updating any other building code”

    Building Energy CodesColorado Energy Officeenergyoffice.colorado.gov (opens in a new tab)Agency pageRetrieved

  • “Any municipality or county that updates any of its building codes after that date must adopt the model code”

    Colorado’s New Model Low Energy and Carbon Code Will Cut Energy Costs, Improve Indoor Air Quality, and Enhance ResiliencyColorado Energy Officeenergyoffice.colorado.gov (opens in a new tab)Agency pageRetrieved

  • “Colorado Model Low Energy and Carbon Code V2”

    Approved State Building Codes, Exhibit A (Rev. 10/2026)Colorado Office of the State Architectosa.colorado.gov (opens in a new tab)Agency pageRetrieved
  • C.R.S. Section 30-28-211, Energy efficient building codesColorado Public Law (mirror of the C.R.S.)colorado.public.law (opens in a new tab)Statute, secondaryRetrieved

  • About an exception

    HB25-1269 Building Decarbonization MeasuresColorado General Assemblyleg.colorado.gov (opens in a new tab)BillRetrieved

  • About how the state adopts codes

    House Bill 22-1362 (enrolled)Colorado General Assemblycontent.leg.colorado.gov (opens in a new tab)BillRetrieved

Tracker cross-checks

Code adoption trackers are a cross-check. They are not Colorado’s own record.

  • DOE’s energycodes.govCross-checkAgrees with the record

    Current State Code: Home Rule; Equivalent Code: 2018 IECC; Enforcement: Jurisdictional; model energy code impacts 2024 IECC

    energycodes.gov (opens in a new tab)Read

  • ICC’s code adoption mapCross-checkAgrees with the record

    State Colorado X (one or more state or local adoptions; no statewide edition), chart as of April 2026

    mitek-us.com (opens in a new tab)Read

  • BCAP’s code status pageCross-checkAgrees with the record

    No statewide code; most jurisdictions adhere to the 2018 IECC or newer (page last modified Apr 7, 2025)

    bcapcodes.org (opens in a new tab)Read

Related pages

Other codes in Colorado