Commercial Solar PV and Battery Requirements

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.

Two limits, and the smaller one applies

The required capacity is the smaller of two figures. The first is Equation 140.10-A: the conditioned floor area of each listed building type multiplied by a capacity factor from Table 140.10-A, which varies by building type and climate zone. The second is the Solar Access Roof Area (SARA) multiplied by a value set by roof slope. A mixed building applies the equation to the floor area of each listed type and adds the results.

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. Roof areas with less than 70 per cent annual solar access are left out.

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 roof values by slope

The roof limit uses two values: 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 roof limit, which is then compared with the floor-area figure.

A calculation carried forward from a 2022-cycle project should be redone against the 2025 factors and roof values rather than reused.

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.

There are three exceptions. No battery is required if the installed PV is less than 15 per cent of the Equation 140.10-A capacity, or if the calculated battery energy capacity is less than 10 kWh. In a multitenant building the battery is sized on tenant spaces over 5,000 square feet, and a single-tenant building under 5,000 square feet needs none.

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.

Because the requirement is the smaller of the floor-area figure and the roof figure, a large roof does not push the array above what the building's floor area calls for, while a small or shaded roof caps it below that. Both numbers have to be worked out to know which one governs.

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