Energy Code Development, Adoption and Compliance: The Benefits of Regularly Updated Codes

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Building energy codes are a powerful tool for incorporating energy efficiency into buildings. In order to better understand the process and the importance of consistent code adoption, this blog will examine the three phases of the energy code cycle: the development of a new model energy code or standard, adoption of the updated code by states and cities and compliance with the code.[1]

What are building energy codes? 

Building codes set minimum standards for residential and commercial building construction and help to ensure the health, safety and welfare of building occupants and communities. More specifically, building energy codes set minimum energy efficiency requirements for new construction, additions and certain renovations. In short, energy codes outline the least energy-efficient building that can be built according to law. These codes address insulation, windows, air sealing, HVAC equipment and other factors that work together to help improve occupant health, increase occupant comfort, reduce emissions and ensure building resilience. Energy codes are also the only building codes that pay customers back over time by lowering the energy use and associated costs of the buildings they occupy. According to the U.S. Department of Energy (DOE), model energy codes for residential and commercial buildings are projected to result in $138 billion in energy cost savings between 2010 and 2040.[2]

1. Development of a new model energy code 

Every three years, residential and commercial model energy codes and standards are updated and made available for adoption by states and local jurisdictions. The International Code Council (ICC) and American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) publish the most widely adopted codes and standards. 

Both the IECC (International Energy Conservation Code) and ASHRAE 90.1 are developed by independent entities that are led by industry experts, allow public participation and use protocols approved by the American National Standards Institute (ANSI). Engagement with stakeholders during the update process is vital in maintaining transparency and allows the public to better understand specific aspects of the code and to voice their concerns with the assurance they will be heard. Regular code development allows for integration of new building technologies and best practices into the latest model code. While this process can be time-consuming, it results in strong codes that are efficient, protective and cost-effective, and often with buy-in across related industries. Model codes and standards are designed to be regularly adopted by municipalities and states. 


The residential and commercial IECC is updated every three years by the ICC and is a fully integrated core section of the ICC suite of health and safety codes. In 2021, the ICC announced it would be moving to a new development process beginning with the 2024 IECC, conducted under ICC’s procedures for standard development, the ANSI-approved ICC Consensus Procedures. In this new process, the ICC Board of Directors established Residential and Commercial Consensus Committees, comprised of representatives from nine different stakeholder categories.[3] Committee members come from a variety of climate zones and have a diversity of experience in buildings and energy efficiency, with a larger goal to have a membership that equitably represents race, gender and socio-economic status. Consensus Committees vote on proposed IECC changes before and throughout the Public Comment process. 2024 IECC Consensus Committees began meeting in October 2021 and hope to complete their work by early 2023. 

ASHRAE 90.1 

ASHRAE has several stakeholder committees that help maintain and update their standards pertaining to energy efficiency, such as the 90.1 commercial energy standard, 90.2 residential energy standard and 189.1 green building standard. ASHRAE 90.1, the most common ASHRAE energy standard adopted by states and municipalities, sets requirements for energy-efficient design of most buildings, except low-rise residential buildings. Like the IECC, it is published every three years. ASHRAE invites the public to participate in committee meetings and submit comments during a public review period. In addition, anyone can submit proposed revisions at any time, and these are made available to the public if they pass through a committee vote.[4] After reviewing public comments, a finalized version of the updated code is published. ASHRAE 90.1-2022 is currently under development and is expected to be released soon. 

2. Adoption of the updated energy code by municipalities and states 

Without an energy code, there would be no minimum thermal comfort standard for buildings. In order to gain the health, safety, cost and climate benefits that come from an energy code, municipalities or states must first adopt the code and then consistently enforce and update it. 

The specifics of code adoption vary slightly by place, but in the Midwest, it typically occurs through an administrative process. This process convenes stakeholders, allows public review of the code and invites proposals for modifications to the model code. Commitment to transparency and public involvement is necessary to ensure the full range of stakeholders have a voice in the process and buy-in with the final version of the code. Sometimes energy code adoption is required by a statute, such as in Illinois where the state is required to adopt a new energy code every three years in concurrence with the publication of the model code.[5] In rare instances, the energy code is written into law, and therefore adoption occurs through a legislative process rather than an administrative one. This makes it much more difficult to routinely update the code and could result in a less transparent process that does not prioritize stakeholder and expert input. In addition, consistently adopting the updated energy code and ensuring a transparent adoption process allow builders and code officials to better predict, understand and adjust to the rapidly changing marketplace of energy-efficient technologies. Nebraska is a state that adopts its energy code legislatively, which may be a reason why adoption is inconsistent. Most recently, Nebraska updated its residential energy code in 2019 (to the 2018 IECC), but before that it had not changed in almost a decade, since the state adopted the 2009 IECC.[6]

3. Compliance with the updated energy code 

The benefits of updated energy codes are only realized once construction is in compliance with code requirements, making enforcement of the energy code critical for building efficiency, health and safety. Code compliance is the responsibility of builders and design professionals, whose work is reviewed and inspected by local code officials.[7]

Educational support for builders, code officials and others working in construction and related industries is necessary to increase understanding and requirements of the updated energy code. Therefore, trainings, resources and technical assistance provided by municipalities, states, professional organizations and other trusted groups are key. Energy code compliance software tools like COMcheck and REScheck, for commercial and residential buildings, respectively, are helpful in determining whether buildings meet energy code requirements. Ultimately, municipalities, states and perhaps most importantly building occupants, will only gain the benefits improved energy codes bring to the extent that buildings comply with the code. 

The importance of regularly adopting updated energy codes 

The newest model energy codes cost-effectively leverage the latest building science and technology to provide greater cost savings to owners and occupants and help assure the construction of safer, healthier and more resilient buildings. Updated energy codes also encourage and support innovation, economic development and community resilience. The model energy codes are carefully integrated with other codes, rigorously reviewed, transparently developed and should be adopted without weakening amendments.  

Due to the cost-effective efficiency improvements made in each model code, cities and states that adopt the latest energy code will reap the greatest benefits. Failing to regularly update energy codes will result in an undertrained workforce falling behind neighboring jurisdictions and an out-of-date building stock that wastes energy. Because the most cost-effective time to install energy efficiency measures is during initial construction, choosing not to build to the latest energy code will result in higher energy use, greater emissions, poorer indoor air quality and increased health care costs for residents and tenants across the life of the building, which is typically anywhere from 50 to 100+ years. The simplest way to ensure energy-efficient, cost-effective, healthy and resilient buildings is to regularly adopt the latest model energy code.