Commercial / California
Solar for New Office Construction
Office buildings are among the occupancies the Energy Code has required to install solar and battery storage since 2023, and their daytime load profile makes them among the best matches for it. The question for a developer is not whether the building will have solar but whether it was designed in during schematics or bolted on during closeout.
Eventure's Role
Eventure works with office developers, architects, and general contractors to size, site, and deliver solar and storage that satisfy Section 140.10, support the building's electrical design, and are ready when the Certificate of Occupancy is.
We bring solar into the project at schematic design, size the Energy Code requirement, coordinate the roof, structure, electrical rooms, and battery location with your architect and engineers, and carry the system through permitting, utility interconnection, inspection, commissioning, and closeout.
Title 24 treatment
Office buildings, financial institutions, and unleased tenant spaces are listed occupancies under Section 140.10. Newly constructed buildings where at least 80% of the floor area is in listed occupancies must install PV and battery storage, with exceptions where the solar-accessible roof area is less than 3% of conditioned floor area or the required system is under 4 kWdc.
Design Considerations
What is different about office buildings.
- Section 140.10 sizingOffice is a listed occupancy. Required PV is the smaller of the floor-area method using the office capacity factor for the climate zone and the Solar Access Roof Area method. A battery sized to the PV system is required as well, with exceptions for very small systems.
- Roof versus carportOffice roofs carry mechanical equipment, screens, and sometimes amenity decks. Carports over the parking field count toward Solar Access Roof Area and often provide more and better-oriented capacity than the roof.
- Tenant spacesUnder the 2025 code, tenant spaces of 2,000 square feet or less with their own meter and HVAC system in multitenant buildings are excluded from the PV calculation. Larger unleased spaces are included, and first-time tenant improvements trigger the requirements.
- Switchgear and electrical room planningInverter output, battery interconnection, and utility metering need space in the main electrical room and a clear path from the roof or carport. We coordinate with the electrical engineer before the room is sized.
Keep Solar Off the Critical Path
Don't let solar be the last thing standing between your project and its Certificate of Occupancy.
On office buildings projects, as on every California building, the Energy Code requirement, the fire authority's review of the battery, the utility's interconnection timeline, and the building's final inspection all depend on the solar scope being designed, permitted, installed, and documented in sequence. We treat it as a scheduled trade from day one.
Solar and the Certificate of Occupancy
Questions
Office Buildings solar, answered.
Is solar required on a new office building in California?
Yes, for newly constructed office buildings where at least 80% of the floor area is in listed occupancy types. The requirement has applied since January 1, 2023 under the 2022 Energy Code and continues, with updated capacity factors, under the 2025 code for permit applications on or after January 1, 2026.
Does an office building also need a battery?
Newly constructed buildings that must install PV under Section 140.10 must also install a battery storage system sized to the PV system, unless an exception applies. The 2025 code also removes the battery requirement for offices and several other occupancies in Climate Zone 1.
Can a solar carport satisfy the requirement?
Yes. Covered parking and carports on the lot count toward Solar Access Roof Area and PV may be installed on them. Many office projects combine a rooftop array with carport canopies.
Related
More commercial building types.
Discuss Your Project
Planning office buildings in California?
Send us the drawings at any stage. We will size the Title 24 requirement, review the roof and electrical approach, and map the path to a Certificate of Occupancy that does not wait on solar.