What changed on January 1
California’s 2025 Energy Code took effect on January 1, 2026, for new buildings and for major additions and alterations. For single-family homes it works through energy budgets that favor heat pumps for heating, cooling, and water heating, along with better HVAC controls and more efficient walls and windows. The Energy Commission is clear that the code doesn’t mandate a specific technology or fuel. It just makes efficient choices the easier path.
Lighting rules you’ll run into
Any permanently installed light fixture has to be high-efficacy and listed under the state’s JA8 standard, with no screw-in sockets. Recessed lights in insulated ceilings need to be airtight and rated for insulation contact. Kitchens, bedrooms, and living spaces need dimmers, while bathrooms, laundry rooms, walk-in closets, and garages need at least one light on a vacancy or occupancy sensor. Under-cabinet lights have to be switched separately.
These rules apply to the parts of the house covered by your permit. Changing a light bulb doesn’t trigger anything.
Heat pumps, without the jargon
A heat pump moves heat instead of making it, so the same unit heats in winter and cools in summer. If your furnace or air conditioner is near the end of its life, a remodel is a natural time to make the switch, and heat pump water heaters work on the same idea. They do need space and electrical capacity, so we look at the panel early in design.
Designing within the rules
None of this gets in the way of good lighting. We layer ambient, task, and accent light, keep color temperatures warm in living spaces, and choose fixtures from the certified list early so nothing has to be swapped out at inspection.
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