For decades, model building energy codes have driven steady efficiency improvements in buildings, saving families and businesses money. But changes under consideration for the next code cycle could stall—or even reverse—those gains, driving up energy bills.
Building energy codes have saved U.S. families and businesses billions of dollars in recent decades, cutting utility bills by ensuring new homes and commercial buildings become increasingly energy efficient with each code update. The International Energy Conservation Code (IECC)—a model code updated every three years—has been an essential tool that states and cities rely on to deliver those savings.
A newly released proposal from the International Codes Council (ICC), which develops the IECC, could change that trajectory. The organization’s draft scope and intent (S&I) document for the 2030 IECC would allow efficiency requirements to stagnate—or even weaken—raising long-term energy costs for families and businesses, increasing vulnerability to future energy price volatility, and setting a precedent for future cycles. Buildings built under these codes will be occupied for decades, so decisions made in this cycle will shape energy costs for the people who live and work in them for years to come.
Proposed changes could weaken codes, raise costs, and stall progress
The ICC’s draft S&I proposes three major changes that, if adopted, would be a major step away from a model code intended to advance energy efficiency.
First, the proposal removes a prior commitment to continuous energy efficiency improvements in each new model code and does not clearly prohibit backsliding (i.e., allowing the code to weaken). Historically, each edition of the IECC has set higher efficiency standards than the previous one. Eliminating that expectation opens the door to stagnation—or, for the first time, regression. A future IECC could weaken energy efficiency in buildings, eroding decades of progress and driving up energy costs for decades to come.
Second, the proposal introduces a cost-effectiveness test based on simple payback that would effectively block code improvements that save homeowners and renters money each month. This flawed approach focuses on upfront costs and short-term savings while ignoring the way buildings are actually financed and occupied. In the real world, most buildings are financed through mortgages or commercial loans, with costs paid over time—just like utility bills. Evaluating efficiency measures as a one-time expense ignores the ongoing savings they provide. For example, a more efficient heating system may increase mortgage payments by a small amount but reduce utility bills by a larger amount each month, leaving the household better off immediately. Yet the simple payback test could reject that improvement.
Third, the proposal would split the IECC into two separate codes, removing all advanced energy efficiency, electrification, and decarbonization measures from the base IECC and sidelining them into the new “IECC-X.” This creates fragmentation, introduces uncertainty, and risks weakening the role of the IECC as a clear and consistent foundation for energy policy. IECC-X is a code no one asked for—jurisdictions already have established pathways for advancing energy efficiency outside the IECC process, including ASHRAE 90.2, Passive House, stretch codes, and the ACEEE-led Next Generation Codes Coalition. Splitting the code risks diverting attention from maintaining and improving the base code and sends a clear message: the base IECC is no longer the place for progress.
These issues are discussed in further detail in comments we recently submitted to the ICC.
ACEEE will defend the IECC against backsliding
ACEEE has participated directly in IECC development for multiple cycles. If these changes are adopted, we would continue to engage in the base IECC development process, specifically to prevent regression. We would not engage in IECC-X, instead putting our resources into more promising pathways outside the IECC to ensure progress continues. Through both channels, we would continue supporting states and cities seeking to improve buildings and lower energy costs.
Scope and intent revision could mark sea change for future code development
It is difficult to see how a framework that allows stagnation—or even backsliding—aligns with ICC’s stated purpose of developing codes that support safe, affordable, and sustainable communities and buildings.
If the S&I is finalized as proposed, policymakers and practitioners looking to advance efficiency and lower costs have options—and a responsibility—to pursue alternative code development pathways to meet their goals.
