DOE is required by the Energy Conservation and Production Act (ECPA), as amended, to review published editions of the national model energy codes—ANSI/ASHRAE/IES Standard 90.1 and the International Energy Conservation Code (IECC)—and issue a determination as to whether the updated edition will improve energy efficiency in commercial and residential buildings, respectively. DOE is provided 12 months to conduct its review and publish its determination in the Federal Register after the updated model code is published. ECPA also requires States to review and/or update their energy codes following the publication of an affirmative DOE determination.
Latest Versions
COMMERCIAL: ANSI/ASHRAE/IES STANDARD 90.1-2022
DOE issued a determination that Standard 90.1-2022 will achieve greater energy efficiency in buildings subject to the code. DOE estimates national savings in commercial buildings of approximately:
- 9.8 percent site energy
- 9.4 percent source energy
- 8.9 percent energy cost
Additional information related to this action, including the official Federal Register publication, is available at Regulations.gov.
State Certification
Upon publication of an affirmative determination, ECPA requires States to certify that they have reviewed the provisions of their commercial building code regarding energy efficiency, and, as necessary, updated their codes to meet or exceed the updated edition of Standard 90.1. Additionally, DOE provides guidance to States on submitting certification statements and requests for deadline extensions. The State Certification deadline for Standard 90.1-2022 is March 06, 2026.
Supporting Analysis
DOE conducted a technical analysis in support of its determination. This analysis assesses Standard 90.1 compared to the previous edition and estimates the associated savings impacts.
Federal Statute for Commercial Buildings
With each new edition of ANSI/ASHRAE/IES Standard 90.1, DOE is required by statute to issue a determination as to whether the updated edition will improve energy efficiency in commercial buildings (42 U.S.C. 6833):
(2)(A) Whenever the provisions of ASHRAE Standard 90.1-1989 (or any successor standard) regarding energy efficiency in commercial buildings are revised, the [DOE] Secretary shall, not later than 12 months after the date of such revision, determine whether such revision will improve energy efficiency in commercial buildings. The [DOE] Secretary shall publish a notice of such determination in the Federal Register.
(B)(i) If the [DOE] Secretary makes an affirmative determination under subparagraph (A), each State shall, not later than 2 years after the date of the publication of such determination, certify that it has reviewed and updated the provisions of its commercial building code regarding energy efficiency in accordance with the revised standard for which such determination was made. Such certification shall include a demonstration that the provisions of such State's commercial building code regarding energy efficiency meet or exceed such revised standard.
(ii) If the [DOE] Secretary makes a determination under subparagraph (A) that such revised standard will not improve energy efficiency in commercial buildings, State commercial building code provisions regarding energy efficiency shall meet or exceed ASHRAE Standard 90.1-1989, or if such standard has been revised, the last revised standard for which the [DOE] Secretary has made an affirmative determination under subparagraph (A).
RESIDENTIAL: 2024 INTERNATIONAL ENERGY CONSERVATION CODE
On December 20, 2024, DOE issued a determination that the 2024 International Energy Conservation Code (IECC) will improve energy efficiency in residential buildings. In support of this determination, DOE conducted a technical analysis evaluating the impacts of the updated code (relative to the previous 2021 IECC edition). DOE estimates national savings of approximately:
- 7.8 percent site energy savings
- 6.8 percent source energy savings
- 6.6 percent energy cost savings
Additional information related to this action, including the official Federal Register publication and docket containing public comments received, is available at Regulations.gov.
State Certification
Upon publication of an affirmative determination, States are required to certify that they have reviewed the provisions of their residential building code regarding energy efficiency, and made a determination as to whether it is appropriate for them to revise their code to meet or exceed the updated edition of the IECC. Additionally, DOE provides guidance to States on submitting certification statements and requests for deadline extensions. State certifications for the 2024 IECC must be submitted by December 30, 2026.
Supporting Analysis
DOE published a technical analysis in support of its determination. This analysis assesses the 2024 IECC compared to the previous edition and estimates the associated savings impact.
Federal Statute for Residential Buildings
With each new edition of the IECC, DOE is required by statute to issue a determination as to whether the updated edition will improve energy efficiency in residential buildings. (42 U.S.C. 6833):
(5)(A) Whenever the CABO Model Energy Code*, 1992, (or any successor of such code) is revised, the [DOE] Secretary shall, not later than 12 months after such revision, determine whether such revision would improve energy efficiency in residential buildings. The [DOE] Secretary shall publish notice of such determination in the Federal Register.
(B) If the [DOE] Secretary makes an affirmative determination under subparagraph (A), each State shall, not later than 2 years after the date of the publication of such determination, certify that it has reviewed the provisions of its residential building code regarding energy efficiency and made a determination as to whether it is appropriate for such State to revise such residential building code provisions to meet or exceed the revised code for which the [DOE] Secretary made such determination.
*As a predecessor to the ICC, the Council of American Building Officials (CABO) was responsible for development of the Model Energy Code (MEC). Contemporary energy codes are referred to and published as the International Energy Conservation Code (IECC)®.
Previous Determinations
Previous DOE determinations surrounding building energy codes are available for reference by states and local governments, as well as other interested stakeholders.