For builders, developers and owners
Solar for new construction, built in from day one
Building a new home, ADU or townhome project in the Bay Area? California requires solar on most new homes, and many need battery-ready wiring too. Starlight Energy handles the solar, battery and electrical work so your project passes inspection and stays on schedule.
What California requires on new homes
Solar has been required on most newly built single-family homes since January 1, 2020. Under the 2025 Energy Code, which applies to permit applications filed on or after January 1, 2026, the rules cover single-family homes, townhouses, duplexes and newly built ADUs.
| Requirement | What it means for your build |
|---|---|
| Solar PV | Required on most new single-family homes. The minimum size is the smaller of what fits on the solar-access roof area or a formula based on climate zone, floor area and number of units. |
| Battery | Not required. A qualifying battery of at least 7.5 kWh can reduce the required solar size by 25%. |
| Battery-ready | Required if electric service is over 125 amps and no battery is installed: a 225-amp main panel busbar, at least four backed-up circuits (including the refrigerator, a light near the main exit and a bedroom outlet), backup interconnection equipment or a 1-inch raceway, and space for a transfer switch within 3 feet of the main panel. |
| If a battery is installed | The home doesn’t have to meet the battery-ready requirements. |
Getting these details right on paper is easy. Getting them right in the walls before drywall is where projects lose time.
How we work with your team
- Plan review. We check your plans and Title 24 report, including the required solar size, roof directions and panel layout, so the design matches what the inspector will look for.
- Rough-in. We set conduit routes from the roof to the panel and the battery-ready circuits before walls close, so nothing has to be opened up later.
- Roof. We coordinate with your roofer and use attachments made for your roofing type.
- Install and inspection. We install the solar, the home battery if you choose one, and the electrical work, then meet the inspector.
- PG&E interconnection. We file the interconnection application for each meter and follow it through to permission to operate.
- Handoff. The homeowner gets a working system, the monitoring app set up and the warranty documents.
Why builders choose Starlight Energy
- Licensed and insured. CSLB #1132072.
- One team for the whole electrical scope. Solar, home batteries, main panels and EV chargers, so nothing falls between trades.
- Owner on every job. You deal directly with the people doing the work.
- 10-year workmanship warranty. In writing, on top of the manufacturer warranties.
- BBB accredited.
- English and Spanish. We communicate clearly with your crews and your buyers.
Projects we take on
- Custom homes
- New ADUs
- Duplexes and townhomes
- Small residential developments
Common questions
Is a battery required on a new home?
No. But a home with electric service over 125 amps and no battery must be battery-ready. Installing a qualifying battery skips the battery-ready requirements and can reduce the required solar size by 25%.
Does a new ADU need its own solar?
Yes, a newly built ADU needs newly installed solar. An existing system on the main house alone doesn’t meet the requirement, though new panels can sometimes be added to it as part of the ADU permit.
Does the solar have to go on the roof?
No. It can go on the house, a carport or another structure on the lot, or be ground-mounted.
What if the roof is too shaded or too small?
Solar isn’t required if there are less than 80 contiguous square feet of roof with good sun, or if the required system would be under 1.8 kW.
Can you work with our Title 24 consultant?
Yes. We review the report with your consultant so the solar size and roof directions match the actual plans.
Sources: California Energy Commission, 2025 Single-Family Solar PV, California Energy Commission, 2025 Single-Family Battery-Ready, California Energy Commission, 2025 Energy Code, California Energy Commission, 2019 Energy Code FAQ.
Have plans for a new build?
Send us your plans and Title 24 report, and we’ll send you a written proposal.