Residential & Multifamily / California
Solar for Mixed-Use New Construction
Residential over retail, office over parking, hotel beside apartments: mixed-use projects combine occupancies that the Energy Code sizes differently, serve through separate meters, and sometimes permit under different code sections. The solar design has to reconcile all of it on a single roof and through a single utility interconnection.
Eventure's Role
Eventure brings the occupancy math, the metering strategy, and the roof plan together during design so the mixed-use building meets its PV and battery requirements without surprises at plan check or at final inspection.
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
Mixed-use buildings are evaluated by occupancy. Nonresidential portions follow Section 140.10, with requirements calculated per building type and summed; multifamily portions follow Section 170.2. Whether battery storage is required depends on the nonresidential share and the multifamily story count.
Design Considerations
What is different about mixed-use.
- The 80% rule and summed requirementsNonresidential PV requirements apply when at least 80% of a building's floor area is in listed occupancy types, and mixed-occupancy buildings calculate the requirement for each type and add them. Multifamily portions follow the multifamily sections. We run the math early so the required size is known before the roof is designed.
- Separate services, one roofGround-floor commercial tenants, residential units, and house loads usually sit on different services. Deciding which service the array feeds, or whether it is split, determines inverter locations, conduit routing, and the interconnection application.
- Podium and roof coordinationMixed-use roofs carry residential mechanical equipment, amenity decks, and sometimes commercial kitchen exhaust. We lay out the array with the architect and mechanical engineer while equipment can still move.
- Tenant improvement timingFirst-time tenant improvements in unleased commercial space are subject to the PV and storage requirements. Planning the shell building's solar with those future spaces in mind avoids a second project a year later.
Keep Solar Off the Critical Path
Don't let solar be the last thing standing between your project and its Certificate of Occupancy.
On mixed-use 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
Mixed-Use solar, answered.
How is the solar requirement calculated for a mixed-use building?
Each occupancy is sized by its own capacity factor and floor area, and the results are added together. The total is then compared with the Solar Access Roof Area method, and the smaller of the two governs. We prepare this calculation during schematic design and coordinate it with the project's energy consultant.
Can one system serve both the residential and commercial portions?
Sometimes, depending on how the services are configured and which utility programs apply. Often the cleanest approach is to serve the house meter or a single large service and treat tenant allocations separately. The decision should be made before the electrical design is complete.
Related
More residential & multifamily building types.
All residential & multifamily · All building types · Where we work
Discuss Your Project
Planning mixed-use 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.