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By the end of this year, the latest edition of the International Energy Conservation Code will be available. Updated every three years, the IECC is designed to assist state and local governments to regulate energy use by providing consistent approaches and metrics nationwide and by standardizing performance targets for new commercial and residential buildings.

What’s New
IECC 2021 contains several updates salient to architects. The International Code Council estimates that the new code requires buildings to be about 10% more energy efficient than the previous edition. New Buildings Institute director of codes Kim Cheslak also notes that it offers more flexibility and clarifies implementation and performance metrics.

The new edition also incorporates research by Pacific Northwest National Laboratory that weighs different energy efficiency measures relative to specific climate zone, occupancy, and building type. Previously, the IECC weighed efficiency measures equally, regardless of project-specific factors. “In the prescriptive path, a project could get equal credit for increased domestic hot water efficiency in an office building, where it has nominal impact, or in a residential building, where it has significant impact,” explains Anica Landreneau, Assoc. AIA, HOK’s director of sustainability, AIA Codes and Standards committee chair, and a voting member of the IECC 2021 update. “For an office building, a measure such as increased efficiency of lighting controls would be more in keeping with the intentions of the code.”

IECC 2021 also specifies mandatory plug load controls in commercial buildings to reduce energy use and waste. “As buildings become more efficient and higher performing … occupant behavior and plug loads can account for 30% or 40% of demand,” Landreneau says. (ASHRAE 90.1 has mandated controls since 2010.)

As we rethink energy and further electrification, we need to think about storage and how to use batteries as part of our building infrastructure.

Mandating the inclusion of electric vehicle infrastructure and charging stations in commercial and residential construction projects looked like a possibility for some time. Landreneau says that language in IECC 2018 about supporting a both efficient and effective use of energy motivated this proposed change: Research has shown that installing electric vehicle infrastructure upfront is more cost-effective than retrofitting existing buildings. The IECC would have required different levels of EV infrastructure based on project square footage, from basic infrastructure such as prewiring and electrical panel capacity for small buildings, to complete charging stations for large buildings. “As we rethink energy and further electrification,” Landreneau says, “we need to think about storage and how to use batteries as part of our building infrastructure.” However, following appeals by the American Gas Association, the American Public Gas Association, the National Association of Home Builders, and the Leading Builders of America, the ICC's board of directors agreed that "the code changes were outside the current scope and intent of the IECC's energy provisions."

The appendices of IECC 2021 include additional voluntary guidelines, including the Zero Code Renewable Energy Appendix. Developed with several green building organizations, such as Architecture 2030, and submitted for consideration into the latest IECC by AIA, the Zero Code requires new commercial, institutional, and mid- to high-rise residential buildings to install or procure enough renewable energy to achieve zero-net carbon. “[The Zero Code] could be adopted as a stretch code [or] could be used to overwrite the base code,” Cheslak says. “It may get picked up as an incentive structure through any number of policies, [such as a] utility program [or] zoning incentives.”

Adoption Challenges
IECC 2021 faces at least one significant challenge: adoption by jurisdictions. New York–based energy code consultant Scott Copp, who participated in the code review and update, says that the process is not straightforward because adoption varies by each jurisdiction. New York, for example, currently adopts IECC 2018 at the state level, but some states adopt older versions, and some opt not to adopt any code statewide, leaving individual municipalities or even communities to decide. “Since each state sets its own process for adoption,” Cheslak says, “there are 51 different adoption processes, all happening on their own schedules and cycles.”

Still, Landreneau believes the new IECC’s “shift to more outcome-based codes” is a step in the right direction for increasing the energy efficiency of buildings and the modernization of code enforcement. Though IECC 2021 doesn't require benchmarking, in which owners regularly report their building's performance, Landreneau says she is hopeful it will become more common. “Then every few years, they [will be] ready for incremental performance requirement increases.”

Editor's note: This article has been updated since first publication to state that proposals to require electric vehicle infrastructure to commercial and residential projects in IECC 2021 were appealed and thus not included in the forthcoming code.