The most widely adopted model energy codes are the International Energy Conservation Code (IECC) and ASHRAE 90.1. The IECC has chapters for residential and commercial building typologies; ASHRAE 90.1 is for buildings other than one or two family attached or detached and multifamily three stories or less.
Residential Buildings Include:
Residential buildings that are three stories or less in height.
- Single Family, Detached Homes
- Duplex, Triplex, Fourplex
- Townhouse
Buildings containing residential and commercial spaces are generally considered separately with respect to compliance with the model energy code.
Applicable Codes:
- International Energy Conservation Code (IECC)
- ASHRAE 90.2
Commercial Buildings Include:
- Large-Scale Multifamily Housing (four stories plus)
- Office Buildings
- Retail Space
- Storage Units
- Industrial Buildings
Commercial also includes: hospitals, warehouses, shopping centers, casinos, schools, restaurants, hotels, and other commercial spaces.
Applicable Codes:
- ASHRAE 90.1
- IECC
Commercial
ASHRAE STANDARD 90.1
Standard 90.1 provides the minimum requirements for the energy-efficient design of sites and buildings, except for low-rise residential buildings. Standard 90.1 provides minimum energy efficiency requirements for designing and constructing systems and equipment in new and existing buildings and sites.
The current ASHRAE 90.1 version is ASHRAE 90.1-2022, published in January 2023.
ASHRAE Revision Process
Proposed changes to ASHRAE Standard 90.1, Energy Standard for Buildings Except Low-Rise Residential Buildings, are developed as addenda to the current edition of the standard. When approved, these changes are published as separate addenda. Every three years those addenda that have been approved are aggregated and incorporated into a new edition of Standard 90.1.
Standard 90.1 is developed and revised according to a process defined by ASHRAE and approved by the American National Standards Institute (ANSI). ASHRAE convenes a Standing Standards Project Committee (SSPC). Members are drawn from government, industry, manufacturers, and users to balance a spectrum of interests. The SSPC oversees all proposed modifications to the standard.
Any interested party may attend and participate in the SSPC's meetings and development activities, including submitting proposed changes, contributing technical information, participating in technical discussions, and, if necessary, appealing SSPC decisions. Interested stakeholders may become non-voting members of the committee, if approved by the SSPC chair. ASHRAE Standard 90.1 is a continuous maintenance standard, meaning any interested person may submit proposed revisions to be considered by the SSPC at any time. After an extensive vetting process, including possible SSPC changes, the SSPC will, by majority vote, forward addenda through ASHRAE's approval process. After an opportunity for appeals, the Board of Directors will approve the addenda for publication.
DOE's Participation
DOE participates in the ASHRAE Standard 90.1 development process by contributing voting and non-voting membership and participation on SSPC-90.1, providing analytical and other technical support to the SSPC, and developing/submitting addenda using the ASHRAE analysis methodology. DOE seeks to incorporate all energy efficiency measures that are cost effective so that ASHRAE Standard 90.1 is a viable standard for state adoption.
For more information on the DOE role in the development of building energy codes, visit the About section of this website.
INTERNATIONAL ENERGY CONSERVATION CODE
The International Energy Conservation Code (IECC) is developed and published by the International Code Council (ICC) and is maintained through a tri-annual public consensus process. The IECC establishes minimum energy efficiency provisions for commercial buildings and low-rise residential (one or two family attached or detached, townhouse, multifamily three stories or less). Within the IECC, there are both prescriptive and performance compliance pathways. The current version of the IECC is the 2021 IECC.
Revision Process
The IECC is revised every three years. Through the 2021 edition, the IECC was updated through the ICC’s governmental consensus process. For the 2024 update, the ICC is utilizing the Standard Development process by convening IECC Residential and Commercial Development Committees, appointed by the ICC Board of Directors, utilizing the ANSI development process, similar to the ASHRAE revision process described above.
Code change proposals may be submitted by any interested party. The proposals are vetted through various Development Committee subcommittees. The subcommittees are composed of subject matter experts drawn from the Development Committee. Each subcommittee vets the merits of the code change proposals. The subcommittees can recommend changes or vote to advance or eliminate the proposal for consideration. The entire Development Committee then has the opportunity to discuss and ultimately vote on the subcommittee’s actions. The Development Committee, as a whole, votes up or down the subcommittee’s actions or elects to send the proposal back to the subcommittee for revision. Ultimately a proposal needs a two-thirds majority affirmative vote to be included as a revision in the updated code.
DOE's Participation
DOE participates in the ICC consensus process to update the commercial building provisions of the IECC to increase energy efficiency in new commercial buildings. Although ASHRAE Standard 90.1 is the commercial model code, DOE participates in the IECC commercial revision process as well as the IECC is the most common commercial code adopted by states and local jurisdictions.
Residential
Residential buildings include one- and two-family attached or detached dwellings, and multi-family buildings three or fewer stories above grade. The process defined under Regulation and Rulemaking is used to develop building energy codes for residential federal buildings and manufactured houses, which are built in a factory and transported to the home site.
INTERNATIONAL ENERGY CONSERVATION CODE
The International Energy Conservation Code (IECC) is developed and published by the International Code Council (ICC) and is maintained through a tri-annual public consensus process.
Revision Process
The IECC is revised every three years. Through the 2021 edition, the IECC was updated through the ICC’s governmental consensus process. For the 2024 update, the ICC is utilizing the Standard Development process by convening IECC Residential and Commercial Development Committees, appointed by the ICC Board of Directors, utilizing the ANSI development process, similar to the ASHRAE revision process described above.
Code change proposals may be submitted by any interested party. The proposals are vetted through various Development Committee subcommittees. The subcommittees are composed of subject matter experts drawn from the Development Committee. Each subcommittee vets the merits of the code change proposals. The subcommittees can recommend changes or vote to advance or eliminate the proposal for consideration. The entire Development Committee then has the opportunity to discuss and ultimately vote on the subcommittee’s actions. The Development Committee, as a whole, votes up or down the subcommittee’s actions or elects to send the proposal back to the subcommittee for revision. Ultimately a proposal needs a two-thirds majority affirmative vote to be included as a revision in the updated code.
DOE's Participation
DOE participates in the ICC consensus process to update the residential building provisions of the IECC to increase energy efficiency in new residential buildings.
For more information on the DOE role in the development of building energy codes, visit the About section of this website.
ASHRAE STANDARD 90.2
ANSI/ASHRAE Standard 90.2, Energy-Efficient Design of Low-Rise Residential Buildings, sets requirements for low-rise residential buildings. The standard is a a performance-based standard comprising the Energy Rating Index (ERI) that closely follows RESNET Standard 301 and includes mandatory requirements.
Revision Process
Proposed changes to ASHRAE Standard 90.2 are developed as addenda to the current edition of the standard. When approved, these changes are published as separate addenda. Standard 90.2 is developed and revised based on a process defined by ASHRAE and approved by the American National Standards Institute (ANSI). ASHRAE convenes a Standing Standards Project Committee (SSPC). Members are drawn from government, industry, manufacturers, and users to balance a spectrum of interests. The SSPC oversees all proposed modifications to the standard.
Any interested party may attend and participate in the SSPC's meetings and development activities, including submitting proposed changes, contributing technical inputs, participating in technical discussions and, if necessary, appealing SSPC decisions. Interested stakeholders may become voting or non-voting members of the committee, if approved by the SSPC chair.
DOE's Participation
DOE supports PNNL's participation in the ASHRAE Standard 90.2 development process by providing analytical and other technical support to the SSPC, and by participating in the development of addenda.