Authored by Corie Anderson, MEEA Building Policy Associate

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

What are building energy codes? 

Building energy codes set minimum energy efficiency requirements for new construction, additions and certain renovations, outlining the least energy-efficient building that can be built according to law. They address insulation, windows, air sealing, HVAC equipment and other factors that work together to improve occupant health, increase occupant comfort, reduce emissions and ensure building resilience. Energy codes are 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). In 2021, the ICC announced it would be moving to a new development process beginning with the 2024 IECC, in which Residential and Commercial Consensus Committees will make final decisions on proposed IECC changes, rather than governmental voting members. Engagement with stakeholders during the update process is vital in maintaining transparency and allows the public to better understand the code and voice 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.

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. 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: Illinois is required to adopt a new energy code every three years in concurrence with the publication of the model code.[3] Other states across the country are also taking action on building code expectations: Washington passed a policy requiring all new commercial buildings to use high-efficiency heating equipment that can run on 100% clean power, and Colorado passed a bill requiring that any municipality that chooses to adopt or update building codes also update to the latest international energy conservation standards. 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 through a transparent process allows builders and code officials to better predict, understand and adjust to the rapidly changing marketplace of energy-efficient technologies. Nebraska adopts its energy code legislatively, which may be a reason why adoption is inconsistent. In 2019, Nebraska updated its residential energy code to the 2018 IECC, but before that it had not changed in almost a decade, since the state adopted the 2009 IECC.[4]

3. Compliance with the updated energy code 

The benefits of updated energy codes are only realized once construction complies with code requirements, making enforcement 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.[5]

As such, trainings, resources and technical assistance for builders and code officials by municipalities, states and trusted professional organizations are key. 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 leverage the latest building science and technology to provide greater cost savings to owners and occupants and assure the construction of safer, healthier and more resilient buildings. They 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.  

Given the cost-effective efficiency improvements made in each model code, cities and states that adopt the latest energy code 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, typically 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. 






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