Building energy codes at a crossroads

Building energy codes set the minimum energy efficiency rules for new and renovated homes. They usually add a bit to upfront construction costs, but the lower energy bills that follow tend to outweigh that extra cost right away, and by a lot more over the life of a mortgage. Government analysis of the 2024 national residential code found net savings for homeowners in every region starting in year one, and separate research found similar savings for commercial buildings.

That system is now facing pushback. In late April, the agencies that oversee federal housing programs dropped a required update to the energy code covering those programs, meaning new or renovated homes in those programs now only need to meet a 2009-era code instead of the more efficient 2021 version, despite the government's own numbers showing the update would have saved households close to $500 a year and more than $15,000 over 30 years. The Department of Energy is also reconsidering how it judges whether codes are cost-effective, in a way critics say downplays energy bill savings and overstates upfront costs. Similar changes are being proposed at the International Code Council, the group that writes the model code many states and cities adopt, and some states are separately moving to weaken or block code updates.

None of this changes existing codes overnight, but it could shape how efficient new construction and major renovations are required to be in the coming years, including in programs tied to federal housing loans. Homeowners curious about their own state's current code requirements can check with their state or local building department.