Local agencies steer 2021 Energy Code toward 10 percent efficiency gains

Approved proposals for the 2021 International Energy Conservation Code (IECC) will bring an estimated 10 percent or more efficiency improvement for both residential and commercial buildings that follow the International Code Council standard. Changes from the 2018 IECC will lower building energy use for decades to come, reduce utility costs, and help mitigate carbon emissions from the built environment, proponents note. The U.S. Department of Energy will release a final analysis of energy savings attributable to code revisions later this year.

Voting on the 2021 IECC proposals took place after more than a year of efforts by a broad coalition of organizations to update the national model energy code. The preliminary results spell the second biggest efficiency gain for the IECC in the last decade and, coalition members contend, put buildings on a path to deliver better comfort, higher productivity, increased value and lower operating costs.

“Homes and buildings account for roughly 40 percent of our energy consumption and carbon emissions, so this is a very big deal,” explains Alliance to Save Energy President Clay Nesler. “It will save consumers and businesses money that can be invested elsewhere in the economy while significantly reducing carbon emissions. It is also the most significant step forward in nearly a decade to putting America’s model energy codes on a pathway towards decarbonization.”

As a model energy code for residential and commercial buildings, IECC sets minimum efficiency standards related to walls, floors, ceilings, lighting, windows, doors, and duct or air leakage. It serves as the go-to basis for states and some cities that can control their building codes to develop local requirements. The IECC is updated every three years through an extensive proposal process and online balloting of eligible voters—individuals primarily representing local governments and related agencies.


When voting for the 2021 IECC opened, local leaders exercised their right to vote and chose to dramatically improve building efficiency, Alliance to Save Energy officials note. Extensive outreach and education by partners including the New Buildings Institute, Energy-Efficient Codes Coalition, Natural Resources Defense Council, Institute for Market Transformation and American Council for an Energy-Efficient Economy helped raise awareness of the balloting.

“Ultimately, the voting reflects an incredible effort by mayors, cities, governors, sustainability directors, and building officials to cast their votes for a code that helps them achieve their energy efficiency and climate goals,” says Energy-Efficient Codes Coalition’s William Fay. “Many state and local leaders rely on the IECC as the basis for their own building codes. After two code cycles of stagnant efficiency improvements, these leaders have exercised their power and delivered a stronger code that will help everyday Americans.”

“This vote says loud and clear that cities and states voting on the IECC want advanced energy efficiency,” adds New Buildings Institute CEO Ralph DiNola. “We are encouraged by the progress and especially the adopted zero energy appendices that allow jurisdictions to go even further than what the IECC calls for in residential and commercial projects.”

“Building code officials, sustainability departments, and state and local agencies made their voices heard, and the message was clear: A strong energy code is the best way to make sure new buildings use less energy, reduce utility bills for consumers, and emit fewer emissions,” says National Resources Defense Council Senior Energy Policy Advocate Lauren Urbanek.

“Codes remain a critical tool to raise the performance of buildings to benefit all residents and occupants. As municipalities and private companies continue to set ambitious targets to reduce energy consumption and carbon emissions, the 2021 IECC will be an excellent tool to bring those goals to fruition,” concludes Institute for Market Transformation Energy Codes Specialist Kimberly Cheslak. “We look forward to continued work with our partners in code advocacy to deploy the new IECC.”

After voting results are certified and challenges cleared, the final 2021 IECC will be released later in 2020, at which time jurisdictions can begin adopting the new standard. — New Buildings Institute, Portland, Ore., www.newbuildings.org


With 1975 baseline of 100 (y axis), the Energy Use Index illustrates the impact of two principal drivers in building and construction design: International Energy Conservation Code (and predecessor Model Energy Code) and ASHRAE Standard 90 — Energy Standard for Buildings Except Low-Rise Residential Buildings. SOURCES: American Council for an Energy-Efficient Economy; U.S. Department of Energy Pacific Northwest National Laboratory