Buildings and Efficiency

Residential Energy Codes

Energy codes are a subset of building codes that establish minimum levels of energy efficiency when constructing a building or renovating an existing one. They can dictate specific materials and practices that must be used, or have some other system to assess energy efficiency in the building. Energy codes set standards for building materials, design, and construction practices for walls, floors, ceilings, lighting, windows, doors and other parts of a building, and they are consistently updated to reflect changes and best practices in technology and methodology. Typically, states have different energy codes for residential and commercial buildings; the code itself will specify which classes of buildings are covered.

In the U.S., states can adopt building codes in a few different ways. Some do not put forth any statewide building codes, instead choosing to implement home rule, which shifts the onus of adoption to local jurisdictions including counties and cities. Other states adopt building codes through legislative action or regulatory mandate. A majority of statewide codes are based on the International Code Council’s I-Codes and/or the ASHRAE standards — energy codes specifically are based on the International Energy Conservation Code (IECC) and ASHRAE 90.1 codes — both of which are updated on a three-year cycle. IECC model codes are most commonly adopted for residential buildings, often with state amendments, although some states will create their own codes with more stringent or more relaxed requirements.

What are I-Codes? The I-Codes are widely adopted in the United States and created by the International Code Council. These codes are created as model rules, meant to be adopted with various amendments in order to better serve each particular jurisdiction. I-Codes include the International Building Code (for commercial structures), the International Residential Code, and the International Energy Conservation Code, among others. The most current versions are the 2024 I-Codes.

What are ASHRAE Codes? ASHRAE codes are the other widely-adopted building codes in the United States, used for commercial building standards. ASHRAE 90.1, developed in 1989, established energy efficiency and performance standards for commercial buildings and has been updated regularly every three years since. This model is meant to be adopted as appropriate by states and/or local jurisdictions, and is referenced in specific sections of the I-Codes. The current version is 90.1-2022.

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Glossary of Terms

States with Policy Enacted

In Progress

Partially Enacted

See States List

Key Resources

Glossary of Terms

Policy Action Toolkit

A policy toolkit with examples of state laws to adopt or update existing energy codes.

2023

Source:

Building Codes Assistance Project

Energy Codes and Policies

A resource hub with strategies, tools, and research products to advance efficient energy codes at the state and local level.

2023

Source:

New Buildings Institute

Policy Explainer: Residential and and Commercial Energy Codes

An analysis of energy codes in residential and commercial buildings, specifically how they are both adopted and developed, and the resources available to make sure they stay up to date.

2023

Source:

Climate XChange

State and National Cost-effectiveness Analysis Reports

An analysis of the associated energy and cost savings of adopting recent editions of the IECC and ASHRAE 90.1 model building codes by state.quantify associated energy and cost savings.

2021

Source:

U.S. DOE

Model Rules

Glossary of Terms

Building Decarbonization Code

A model building code that amends the 2021 IECC to deliver carbon neutral buildings.

2021

Source:

New Buildings Institute

Model States

Glossary of Terms

California

The statewide energy code for residential construction is the California 2022 Energy Code.

2021

Establishing Policies

California State Energy Code (2021)

Rhode Island

The statewide energy code for residential construction is 2018 IECC with amendments.

2021

Establishing Policies

Vermont

The statewide energy code for residential construction is the Vermont 2024 Residential Building Energy Standards.

2023

Establishing Policies

Washington

The statewide energy code for residential construction is the Washington State 2021 Energy Code.

2024

Establishing Policies

Washington State Energy Code (2024)

Glossary of Terms

Filters

Status	State Sort descending	Region	YR Enacted
Enacted	Alabama Empty column The statewide energy code for residential construction is 2018 IECC. Establishing Policies Alabama State Energy Code (2022) Empty column	Southeast	2022
Not Enacted	Alaska Empty column Residential energy codes are statewide building codes that dictate the energy performance requirements of newly constructed residential buildings. Empty column	West
Not Enacted	Arizona Empty column Residential energy codes are statewide building codes that dictate the energy performance requirements of newly constructed residential buildings. Empty column	Southwest
Enacted	Arkansas Empty column The statewide energy code for residential construction is 2009 IECC. Establishing Policies Arkansas State Energy Code (2014) Empty column	Southeast	2014
Enacted	California Empty column The statewide energy code for residential construction is the California 2022 Energy Code. Establishing Policies California State Energy Code (2021) Empty column	West	2021
Not Enacted	Colorado Empty column Residential energy codes are statewide building codes that dictate the energy performance requirements of newly constructed residential buildings. Empty column	West
Enacted	Connecticut Empty column The statewide energy code for residential construction is 2021 IECC with amendments. Establishing Policies Connecticut State Energy Code (2022) Empty column	Northeast	2022
Enacted	Delaware Empty column The statewide energy code for residential construction is 2018 IECC. Establishing Policies Delaware State Energy Code (2020) Empty column	Southeast	2020
Enacted	Florida Empty column The statewide energy code for residential construction is 2021 IECC with amendments. Establishing Policies Florida State Energy Code (2023) Empty column	Southeast	2023
Enacted	Georgia Empty column The statewide energy code for residential construction is 2015 IECC with amendments. Establishing Policies Georgia State Energy Code (2020) Empty column	Southeast	2020
Enacted	Hawai‘i Empty column The statewide energy code for residential construction is 2018 IECC with amendments. Establishing Policies Hawai‘i State Energy Code (2021) Empty column	West	2021
Enacted	Idaho Empty column The statewide energy code for residential construction is 2018 IECC with amendments. Establishing Policies Idaho State Energy Code (2020) Empty column	West	2020
Enacted	Illinois Empty column The statewide energy code for residential construction is 2021 IECC with amendments. Establishing Policies Illinois State Energy Code (2023) Empty column	Midwest	2023
Enacted	Indiana Empty column The statewide energy code for residential construction is 2018 IECC. Establishing Policies Indiana State Energy Code (2019) Empty column	Midwest	2019
Enacted	Iowa Empty column The statewide energy code for residential construction is 2012 IECC with amendments. Establishing Policies Iowa State Energy Code (2014) Empty column	Midwest	2014
Not Enacted	Kansas Empty column Residential energy codes are statewide building codes that dictate the energy performance requirements of newly constructed residential buildings. Empty column	Midwest
Enacted	Kentucky Empty column The statewide energy code for residential construction is IECC 2009 with amendments. Establishing Policies Kentucky State Energy Code (2014) Empty column	Southeast	2014
Enacted	Louisiana Empty column The statewide energy code for residential construction is 2021 IECC with amendments. Establishing Policies Louisiana State Energy Code (2022) Empty column	Southeast	2022
Enacted	Maine Empty column The statewide energy code for residential construction is 2015 IECC. Establishing Policies Maine State Energy Code (2020) Empty column	Northeast	2020
Enacted	Maryland Empty column The statewide energy code for residential construction is 2021 IECC with amendments. Establishing Policies Maryland State Energy Code (2023) Empty column	Southeast	2023
Enacted	Massachusetts Empty column The statewide energy code for residential construction is 2021 IECC. Establishing Policies Massachusetts State Energy Code (2022) Empty column	Northeast	2022
Enacted	Michigan Empty column The statewide energy code for residential construction is 2015 IECC with amendments. Establishing Policies Michigan State Energy Code (2015) Empty column	Midwest	2015
Enacted	Minnesota Empty column The statewide energy code for residential construction is 2012 IECC with amendments. Establishing Policies Minnesota State Energy Code (2014) Empty column	Midwest	2014
Not Enacted	Mississippi Empty column Residential energy codes are statewide building codes that dictate the energy performance requirements of newly constructed residential buildings. Empty column	Southeast
Not Enacted	Missouri Empty column Residential energy codes are statewide building codes that dictate the energy performance requirements of newly constructed residential buildings. Empty column	Midwest
Enacted	Montana Empty column The statewide energy code for residential construction is 2021 IECC with amendments. Establishing Policies Montana State Energy Code (2022) Empty column	West	2022
Enacted	Nebraska Empty column The statewide energy code for residential construction is 2018 IECC. Establishing Policies Nebraska State Energy Code (2019) Empty column	Midwest	2019
Enacted	Nevada Empty column The statewide energy code for residential construction is 2021 IECC. Establishing Policies Nevada State Energy Code (2021) Empty column	West	2021
Enacted	New Hampshire Empty column The statewide energy code for residential construction is 2018 IECC. Establishing Policies New Hampshire State Energy Code (2022) Empty column	Northeast	2022
Enacted	New Jersey Empty column The statewide energy code for residential construction is 2021 IECC. Establishing Policies New Jersey State Energy Code (2022) Empty column	Northeast	2022
Enacted	New Mexico Empty column The statewide energy code for residential construction is 2021 IECC with amendments. Establishing Policies New Mexico State Energy Code (2024) Empty column	Southwest	2024
Enacted	New York Empty column The statewide energy code for residential construction is 2018 IECC with amendments. Establishing Policies New York State Energy Code (2020) Empty column	Northeast	2020
Enacted	North Carolina Empty column The statewide energy code for residential construction is 2015 IECC. Establishing Policies North Carolina State Energy Code (2018) Empty column	Southeast	2018
Not Enacted	North Dakota Empty column Residential energy codes are statewide building codes that dictate the energy performance requirements of newly constructed residential buildings. Empty column	Midwest
Enacted	Ohio Empty column The statewide energy code for residential construction is 2018 IECC with amendments. Establishing Policies Ohio State Energy Code (2018) Empty column	Midwest	2018
Enacted	Oklahoma Empty column The statewide energy code for residential construction is 2018 IRC with amendments aligning with 2018 IECC. Establishing Policies Oklahoma State Energy Code (2022) Empty column	Southwest	2022
Enacted	Oregon Empty column The statewide energy code for residential construction is the Oregon 2023 Residential Specialty Code. Establishing Policies Oregon State Energy Code (2023) Empty column	West	2023
Enacted	Pennsylvania Empty column The statewide energy code for residential construction is 2018 IECC. Establishing Policies Pennsylvania State Energy Code (2021) Empty column	Northeast	2021
Enacted	Rhode Island Empty column The statewide energy code for residential construction is 2018 IECC with amendments. Establishing Policies Rhode Island State Energy Code (2021) S 0855A (2023) Empty column	Northeast	2021
Enacted	South Carolina Empty column The statewide energy code for residential construction is 2009 IECC. Establishing Policies South Carolina State Energy Code (2012) Empty column	Southeast	2012
Not Enacted	South Dakota Empty column Residential energy codes are statewide building codes that dictate the energy performance requirements of newly constructed residential buildings. Empty column	Midwest
Enacted	Tennessee Empty column The statewide energy code for residential construction is 2018 IECC with amendments. Establishing Policies Tennessee State Energy Code (2020) Empty column	Southeast	2020
Enacted	Texas Empty column The statewide energy code for residential construction is 2015 IECC. Establishing Policies Texas State Energy Code (2015) Empty column	Southwest	2015
Enacted	Utah Empty column The statewide energy code for residential construction is 2015 IECC. Establishing Policies Utah State Energy Code (2019) Empty column	West	2019
Enacted	Vermont Empty column The statewide energy code for residential construction is the Vermont 2024 Residential Building Energy Standards. Establishing Policies Residential Building Energy Standards (2023) Vermont State Energy Code (2019) Empty column	Northeast	2023
Enacted	Virginia Empty column The statewide energy code for residential construction is 2021 IECC with amendments. Establishing Policies Virginia State Energy Code (2023) Empty column	Southeast	2023
Enacted	Washington Empty column The statewide energy code for residential construction is the Washington State 2021 Energy Code. Establishing Policies Washington State Energy Code (2024) Empty column	West	2024
Enacted	West Virginia Empty column The statewide energy code for residential construction is 2015 IECC with amendments. Establishing Policies West Virginia State Energy Code (2022) Empty column	Southeast	2022
Enacted	Wisconsin Empty column The statewide energy code for residential construction is 2009 IECC. Establishing Policies Wisconsin State Energy Code (2015) Empty column	Midwest	2015
Not Enacted	Wyoming Empty column Residential energy codes are statewide building codes that dictate the energy performance requirements of newly constructed residential buildings. Empty column	West

Residential Energy Codes

Key Resources

Model Rules

Model States

Residential Energy Codes By State