Gas furnaces and stoves are quietly dropping off new-construction plans in two of the country’s biggest building markets. New York’s All-Electric Buildings Act and California’s 2025 Energy Code both kicked in January 1, and six months in, the rules are reshaping how design teams spec mechanical systems.
What the all-electric building codes require
New York’s law bans fossil-fuel equipment in most new buildings under seven stories, with larger and more complex buildings phased in by the end of 2028. No gas hookups, no gas appliances, electric heat pumps instead. California took a slightly different route through its energy code rather than an outright ban, but the effect rhymes: new homes are expected to run all-electric, with heat pumps for space conditioning and water heating treated as the baseline. The state estimates roughly $4.8 billion in energy savings over the code cycle.
How the electrification mandates change construction
For builders, the shift lands in the mechanical room and the service entrance. Heat pumps draw differently than gas furnaces, so electrical loads, panel sizing, and utility coordination all move up the critical path. Oregon is making heat pumps the default for cooling, nudging builders away from conventional AC. Colorado, a home-rule state without a statewide energy code, is steering local jurisdictions toward high-efficiency electric systems as they update.
The map is filling in. Connecticut, Delaware, Maine, Maryland, Massachusetts, New Jersey, and New York are all working toward 2024 IECC adoption. That’s a lot of square footage about to share one direction of travel, even if the timelines don’t line up.
The codes don’t stand alone. They sit alongside LEED v5’s new embodied-carbon rules and experiments like Meta’s mass-timber data centers, all pointing the same way. Operating carbon is getting regulated. The rest is catching up.