R329 Solar Energy Systems — 2025 California Residential Code

Solar energy systems shall comply with the provisions of this section.

Solar thermal systems shall be designed and installed in accordance with the California Plumbing Code and the California Fire Code.

Photovoltaic ( PV ) systems shall be designed and installed in accordance with Sections R329.3.1 through R329.8.1 and the manufacturer’s installation instructions. The electrical portion of solar PV systems shall be designed and installed in accordance with the California Electrical Code.

R329.3.1 Equipment listings. Photovoltaic panels and modules shall be listed and labeled in accordance with UL 1703 or with both UL 61730-1 and UL 61730-2. Inverters shall be listed and labeled in accordance with UL 1741. Systems connected to the utility grid shall use inverters listed for utility interaction. Mounting systems listed and labeled in accordance with UL 2703 shall be installed in accordance with the manufacturer’s installation instructions and their listings. Building-integrated photovoltaic (BIPV) roof coverings and BIPV roof assemblies shall be listed and labeled in accordance with UL 7103.

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BUILDING PLANNING

Rooftop-mounted photovoltaic panel systems installed on or above the roof covering shall be designed and installed in accordance with this section.

R329.4.1 Structural requirements. Rooftop-mounted photovoltaic panel systems shall be designed to structurally support the system and withstand applicable gravity loads in accordance with Chapter 3. The roof on which these systems are installed shall be designed and constructed to support the loads imposed by such systems in accordance with Chapter 8.

R329.4.1.1 Roof load. Portions of roof structures not covered with photovoltaic panel systems shall be designed for dead loads and roof loads in accordance with Sections R301.4 and R301.6. Portions of roof structures covered with photovoltaic panel systems shall be designed for the following load cases:

1. Dead load (including photovoltaic panel weight) plus snow load in accordance with Table R301.2.
2. Dead load (excluding photovoltaic panel weight) plus roof live load or snow load, whichever is greater, in accordance with Section R301.6.

R329.4.1.2 Wind load. Rooftop-mounted photovoltaic panel or module systems and their supports shall be designed and installed to resist the component and cladding loads specified in Table R301.2.1(1), adjusted for height and exposure in accordance with Table R301.2.1(2).

R329.4.2 Fire classification. Rooftop-mounted photovoltaic panel systems shall have the same fire classification as the roof assembly required in Section R902.

R329.4.3 Roof penetrations. Roof penetrations shall be flashed and sealed in accordance with Chapter 9.

Building-integrated photovoltaic (BIPV) systems shall be designed and installed in accordance with Sections R329.5.1 through R329.5.2.

R329.5.1 BIPV roofing systems. BIPV roofing systems shall comply with Section R905.15. BIPV roof panels shall comply with Section R905.16.

R329.5.1.1 Fire classification. Building-integrated photovoltaic systems shall have a fire classification in accordance with Section R902.3.

R329.5.2 BIPV exterior wall coverings and fenestration. BIPV exterior wall coverings and fenestration shall comply with Section R705.

Roof access, pathways and setback requirements shall be provided in accordance with Sections R329.6.1 through R329.6.2.1. Access and minimum spacing shall be required to provide emergency access to the roof, to provide pathways to specific areas of the roof, provide for smoke ventilation opportunity areas, and to provide emergency egress from the roof.

Exceptions:

1. Detached, nonhabitable structures, including but not limited to detached garages, parking shade structures, carports, solar trellises and similar structures, shall not be required to provide roof access.
2. Roof access, pathways and setbacks need not be provided where the enforcing agency has determined that rooftop operations will not be employed.
3. These requirements shall not apply to roofs with slopes of 2 units vertical in 12 units horizontal (17-percent slope) or less.
4. BIPV systems listed in accordance with UL 3741, where the removal or cutting away of portions of the BIPV system during firefighting operations has been determined to not expose a firefighter to electrical shock hazards.

R329.6.1 Pathways. Not fewer than two pathways, on separate roof planes from lowest roof edge to ridge and not less than 36 inches (914 mm) wide, shall be provided on all buildings. Not fewer than one pathway shall be provided on the street or driveway side of the roof. For each roof plane with a photovoltaic array, a pathway not less than 36 inches wide (914 mm) shall be provided from the lowest roof edge to ridge on the same roof plane as the photovoltaic array, on an adjacent roof plane, or straddling the same and adjacent roof planes. Pathways shall be over areas capable of supporting firefighters accessing the roof. Pathways shall be located in areas with minimal obstructions such as vent pipes, conduit, or mechanical equipment.

R329.6.2 Setback at ridge. For photovoltaic arrays occupying not more than 33 percent of the plan view total roof area, not less than an 18-inch (457 mm) clear setback is required on both sides of a horizontal ridge. For photovoltaic arrays occupying more than 33 percent of the plan view total roof area, not less than a 36-inch (914 mm) clear setback is required on both sides of a horizontal ridge.

R329.6.2.1 Alternative setback at ridge. Where an automatic sprinkler system is installed within the dwelling or townhouse in accordance with NFPA 13D or Section R309, setbacks at ridges shall comply with one of the following:

1. For photovoltaic arrays occupying not more than 66 percent of the plan view total roof area, not less than an 18-inch (457 mm) clear setback is required on both sides of a horizontal ridge.
2. For photovoltaic arrays occupying more than 66 percent of the plan view total roof area, not less than a 36-inch (914 mm) clear setback is required on both sides of a horizontal ridge.

R329.6.3 Emergency escape and rescue openings. Panels and modules installed on dwellings or townhouses shall not be placed on the portion of a roof that is below an emergency escape and rescue opening. A pathway not less than 36 inches (914 mm) wide shall be provided to the emergency escape and rescue opening.

Exception: BIPV systems listed in accordance with UL 3741, where the removal or cutting away of portions of the BIPV system during firefighting operations has been determined to not expose a firefighter to electrical shock hazards.

BUILDING PLANNING

R329.6.4 Building-integrated photovoltaic (BIPV) systems. Where building-integrated photovoltaic (BIPV) systems are installed in a manner creating areas with electrical hazards that are hidden from view, markings shall be provided to identify the hazardous areas to avoid for ladder placement. The markings shall be reflective and be visible from grade beneath the eaves or other location approved by the fire code official.

Exception: BIPV systems listed in accordance with UL 3741, where the removal or cutting away of portions of the BIPV system during firefighting operations have been determined to not expose a firefighter to electrical shock hazards.

Elevated PV support structures used as an accessory structure shall comply with either Section R329.7.1 or R329.7.2. Elevated PV support structures shall be considered a roof for the purposes of establishing the number of stories and fire separation distances.

Exception : Elevated PV support structures that are installed over agricultural use.

R329.7.1 PV panels installed over open-grid framing or noncombustible deck. Elevated PV support structures with PV panels installed over open-grid framing or over a noncombustible deck shall have PV panels tested, listed and labeled with a fire type rating in accordance with UL 1703 or with both UL 61730-1 and UL 61730-2. Photovoltaic panels marked “not fire rated” shall not be installed on elevated PV support structures.

R329.7.2 PV panels installed over a roof assembly. Elevated PV support structures with a PV panel system installed over a roof assembly shall have a fire classification in accordance with Section R902.4 and Section R329.4.

Ground-mounted photovoltaic (PV) panel systems shall be designed and installed in accordance with Section R301.

R329.8.1 Fire separation distances. Ground-mounted photovoltaic systems shall be subject to the fire separation distance requirements determined by the enforcing agency.

R329.8.2 Ground-mounted photovoltaic arrays. Ground mounted photovoltaic arrays shall comply with this section and the Cali- fornia Electrical Code. Setback requirements shall not apply to ground-mounted, free-standing photovoltaic arrays. A clear, brush- free area of 10 feet (3048 mm) shall be required for ground-mounted photovoltaic arrays.

R329.8.3 Locations of DC conductors. Conduit, wiring systems and raceways for photovoltaic circuits shall be located as close as possible to the ridge or hip or valley and from the hip or valley as directly as possible to an outside wall to reduce trip hazards and maximize ventilation opportunities. Conduit runs between sub arrays and to DC combiner boxes shall be installed in a manner that minimizes the total amount of conduit on the roof by taking the shortest path from the array to the DC combiner box. The DC combiner boxes shall be located such that conduit runs are minimized in the pathways between arrays. DC wiring shall be installed in metallic conduit or raceways when located within enclosed spaces in a building. Conduit shall run along the bottom of load bearing members.