Introduction: Why Title 24 matters in 2025
California has some of the most ambitious energy standards in the nation, and every few years, they get stricter. The 2025 update to Title 24, also known as the Building Energy Efficiency Standards, impacts almost every residential project – from new ADUs to whole-home remodels.
If you’re planning construction, you’ll need to understand what the new code requires, what’s optional, and how it affects your budget and design choices. This guide explains Title 24 in plain English and helps you prepare.
What is Title 24?
Title 24 is part of the California Code of Regulations. It sets energy-efficiency standards for residential and commercial buildings to reduce greenhouse gas emissions and lower long-term utility costs.
For homeowners, it means that every remodel, addition, or new build must meet minimum standards for:
- Insulation and building envelope
- Windows and glazing
- Heating, ventilation, and air conditioning (HVAC)
- Water heating
- Lighting and controls
- Solar readiness (and in some cases, solar installation)
What’s new in the 2025 standards?
The 2025 Title 24 update focuses on pushing homes closer to carbon neutrality. Key changes include:
- Stricter insulation and envelope requirements: higher R-values for walls, roofs, and floors.
- Heat pump priority: new homes must use heat pump HVAC systems or justify alternatives.
- Expanded solar and storage mandates: larger homes and ADUs may need on-site solar plus battery readiness.
- Smarter lighting controls: dimmers, occupancy sensors, and daylight controls are now more broadly required.
- Water heating efficiency: stronger requirements for heat pump water heaters.
How Title 24 affects ADUs and additions
ADUs are fully subject to Title 24. Even a small garage conversion must meet insulation and lighting rules, and detached ADUs may need solar-ready roofs or actual solar panels depending on size.
For additions:
- A small addition (≤700 sq ft) may only require compliance in the new portion.
- Large additions (>700 sq ft) often trigger whole-house performance checks.
- Envelope upgrades (insulation, windows, doors) are commonly required.
Cost impacts: what homeowners should expect
Complying with Title 24 does add costs, but many pay back quickly through energy savings. Typical impacts include:
- Insulation upgrades: +$3k–$7k depending on scope.
- Heat pump HVAC systems: $12k–$20k installed, but rebates are available.
- Heat pump water heater: $3k–$5k, often with rebates covering up to half.
- Solar panels: $15k–$25k depending on system size.
- Lighting controls: +$500–$1,500 for dimmers and sensors.
Long-term benefits: why Title 24 is worth it
- Lower energy bills: savings average 25–40% compared to older homes.
- Healthier indoor air: heat pumps and ventilation requirements improve comfort.
- Future-proofing: homes that meet 2025 standards will hold higher resale value.
- Incentives: California and utilities offer rebates for many compliant upgrades.
Common homeowner misconceptions
- “I’m only remodeling a bathroom, so Title 24 doesn’t apply.” – It does, especially for lighting, ventilation, and water heating.
- “Solar is always optional.” – Not for all new ADUs or large additions.
- “The inspector won’t check.” – Title 24 is tied to plan checks and final inspections, so compliance is required.
How BERG helps clients navigate Title 24
At BERG, we design every project with compliance in mind from the start. Our process includes:
- Early coordination with Title 24 energy consultants.
- Cost-benefit analysis of required vs. optional upgrades.
- Integration of solar, storage, and efficiency into architectural design.
- Guidance on rebates and financing to offset upfront costs.
Conclusion: building smarter with Title 24
California’s 2025 Title 24 standards raise the bar, but they also create an opportunity. By meeting the new code, homeowners aren’t just checking boxes – they’re investing in healthier, more efficient, and more valuable homes.
Planning a remodel or ADU? Contact BERG to learn how we design and build for Title 24 compliance while protecting your budget.
