Commercial Solar PV and Battery Requirements
Many newly constructed nonresidential buildings must install a PV system, sized from Solar Access Roof Area at 14 watts per square foot on low-slope roofs and 18 on steep-slope. Any building required to have PV must also have battery storage.
Which buildings are caught
The requirement applies to newly constructed buildings of the types the section lists. It also reaches mixed occupancy buildings, where at least 80 per cent of the floor area serves one or more of those listed types.
The 80 per cent test is what decides genuinely mixed developments, and it is assessed on floor area rather than on what the building is called. A building whose listed uses fall below that share is outside the requirement even though it contains them.
SARA: the roof decides the size
System size is driven by Solar Access Roof Area — not by the building's energy use, and not by a percentage of its load. SARA includes the roof space capable of structurally supporting a PV system, plus roof space on covered parking areas, carports and other newly constructed structures on the site that can support PV.
Two consequences follow. Carports and covered parking are in scope, which surprises people who assumed the building's own roof was the whole calculation. And structural capacity is part of the definition, so the structural design and the energy compliance are coupled.
Two watts-per-square-foot values, changed for 2025
The 2025 cycle changed the SARA formula inputs. There are now two values by roof type: 14 W/sq ft for low-slope roofs and 18 W/sq ft for steep-slope roofs. A building with both roof types sums the two to reach its total required capacity.
Anyone carrying a calculation forward from a 2022-cycle project needs to redo it. This is one of the changes that does not appear in a headline summary of the cycle and materially affects the answer.
Battery storage comes with it
Any building required to have a PV system must also have battery storage. The battery has to meet the minimum qualification requirements of Reference Joint Appendix JA12, and both its rated energy capacity and its rated power capacity are set by the section's equations.
Note that both capacities are specified. Energy capacity is how much the battery holds; power capacity is how fast it can deliver. A battery meeting one and not the other does not comply, and the two are independent product characteristics.
Why this belongs in early design
Every input here is architectural or structural. Roof area, roof slope, whether carports exist, whether the structure can carry an array, and where a battery will physically sit with its clearances and fire separation. None of it can be resolved by the energy consultant alone, and none of it is cheap to change once the structure is designed.
The requirement is also easy to underestimate because it is sized from roof area rather than from load. A building with modest energy use and a large roof can owe a substantial array — which is the opposite of the intuition most project teams start with.