Title 24 for Remodels: What the 2025 California Energy Code Means for Your Project

Short answer: Title 24, Part 6 is California’s building energy code. It applies to remodels, additions and equipment replacements — not just new homes. Permits filed on or after January 1, 2026 must meet the 2025 standards, which favor heat-pump heating and water heating and tighten insulation, window and ventilation requirements. If you are planning a kitchen, bathroom, addition, roof, water heater or HVAC project in San Ramon, this is what changes for you.

What the 2025 code means for a remodel

Project	What Title 24 (2025) touches
Kitchen or bathroom remodel	High-efficacy (LED) lighting with the required controls; exhaust fans with the required airflow and controls; new windows must meet current U-factor and solar heat gain limits.
Room addition or ADU	Full envelope requirements for the new space: wall, ceiling and floor insulation, window performance, air sealing and ventilation; the energy budget calculation now favors heat pumps for space and water heating.
Water heater replacement	New equipment must meet current efficiency rules; heat-pump water heaters are favored in the energy budget and tankless gas units remain an option where allowed.
HVAC replacement	Duct leakage testing and sealing are required in most climate zones when ducts or equipment are replaced; new systems must meet current efficiency minimums.
Re-roof	Cool-roof requirements apply to many low-slope and some steep-slope roofs depending on climate zone and roof type.
Attic insulation upgrade	Prescriptive ceiling insulation targets are R-22 with wood framing (or an equivalent U-factor) in the 2025 standards; deeper insulation is common and pays back in San Ramon’s summers.

The three biggest changes in the 2025 cycle

Heat pumps favored: the energy budget for single-family homes and low-rise multifamily now credits heat-pump space and water heating.
Electric-ready provisions: pre-wiring and pre-plumbing for future heat-pump water heaters and electric cooking in several building types.
Tighter envelope and ventilation: prescriptive insulation, window and ventilation requirements were tightened across most climate zones.

How compliance works on a real project

Your plans include the Title 24 compliance forms (prescriptive or performance method). For additions and larger alterations, an energy consultant runs the performance model.
Installers document the equipment and duct testing (HERS verification) where required.
The city inspector checks the installed insulation, lighting, windows and equipment against the approved forms.

We prepare and file these documents with every permit we pull, and we choose equipment that passes the first time.

Frequently asked questions

Does Title 24 apply if I only replace my water heater?

Yes. Equipment replacements are alterations under Part 6 and must meet current requirements for the component being replaced.

Do I have to switch to electric appliances?

The 2025 standards favor heat pumps in the energy budget calculation but do not ban gas equipment in existing homes; the right choice depends on your panel, gas service and goals. We walk through both.

Will Title 24 make my remodel more expensive?

Some line items (better windows, duct testing) add cost; others (LED lighting, insulation) pay back quickly through lower bills and comfort. Planning for it early avoids the expensive version: failing inspection.

What climate zone is San Ramon?

San Ramon and most of central Contra Costa County fall in California climate zone 12, which has hot summers and cool winters — insulation, shading and duct sealing matter a lot here.

Plan a code-compliant remodel: free estimate or call (510) 725-4073.

Sources: California Energy Commission, 2025 Building Energy Efficiency Standards for Residential and Nonresidential Buildings (Title 24, Part 6), effective January 1, 2026; CEC summary of 2025 code changes. General information for planning; compliance is verified on the approved plans.