Title 24 (2025 cycle): what changed and what it means for your remodel

When we say 'Title 24 2025,' we mean the 2022 Building Energy Efficiency Standards as updated by the California Energy Commission for the 2025 code cycle. The CEC's official Title 24 Part 6 page is the authoritative reference — every cycle the standards tighten, and the 2025 cycle is the biggest residential shift since 2008 CEC Title 24 Part 6 Building Energy Efficiency Standards.

Local jurisdictions adopt the state code on a published date and may add 'reach' amendments on top. LA, San Francisco, Berkeley, and Oakland all have local reach codes that go further than state Title 24, particularly on gas-line restrictions for new construction.

Under the 2025 cycle, the prescriptive compliance path for new low-rise residential and most major alterations assumes electric heat pumps for both space and water heating. You can still install gas — but you must pay the 'compliance margin' elsewhere in the building (better insulation, better windows, lower HVAC duct leakage, etc.), and the performance modeling has to work out.

What this means in practice: a remodel that adds a new HVAC system or replaces a water heater is almost always cheaper to permit if you go electric. The line-item hardware cost is higher, but the avoidance of the performance-path compliance documentation alone usually offsets it. ENERGY STAR's heat pump documentation gives a useful spec baseline ENERGY STAR heat pump program.

Three categories trigger Title 24 compliance documentation: new conditioned space (any addition over 0 sqft, plus garage conversions to habitable space), alteration of more than 50% of an existing space, and any HVAC, water-heater, or window replacement that meets the alteration thresholds in the code.

Kitchen remodels and bathroom remodels often think they're exempt and aren't — replacing the window over the sink, adding insulation in a wall that gets opened up, or moving the range hood all touch Title 24. The CEC's residential alterations guide is the authoritative source CEC Residential Alterations Compliance.

The 2025 cycle dropped the prescriptive maximum U-factor to 0.30 and SHGC to 0.23 in most LA and Bay Area climate zones. That's vinyl or fiberglass dual-pane low-e — aluminum-frame windows fail prescriptive in every CA climate zone and require an offsetting upgrade elsewhere.

If you're matching existing windows for aesthetics on a historic property, the code allows a 'replacement-in-kind' exception for like-for-like single-pane retrofits — but this is narrow and HPOZ areas have their own additional rules.

ADUs follow single-family Title 24 rules but with several CEC clarifications: detached ADUs under 700 sqft don't trigger solar requirements; ADUs added to a property with existing solar usually don't need additional panels. CEC's ADU-specific guidance is worth bookmarking California HCD ADU memos (Title 24 references).

Multifamily over 3 stories follows nonresidential Title 24 (Part 6 nonres). The cost impact is meaningful: commercial HVAC sizing, mandatory commissioning, and continuous monitoring requirements all kick in.