CA rooftop PV fire setbacks (2025 codes, in force since 2026-01-01).

Residential (CRC R329.6):

•  Ridge. 18" clear on both sides of the ridge, while the array covers ≤33% of the roof's plan area. Over 33%, it's 36". With fire sprinklers, the threshold is 66% instead of 33%.

•  Paths. At least two 36"-wide paths from eave to ridge, on separate roof planes. At least one on the street / driveway side. Each plane with modules needs a path on it or on a plane next to it.

•  Egress. No modules on the roof below an emergency escape opening (e.g. a bedroom window). A 36" path to that opening.

•  Exempt. Roofs at 2:12 or flatter. Detached non-habitable buildings (garage, shed).

Commercial (CFC 1205.3):

•  4' clear around the roof edge (6' if both sides of the building are over 250')

•  interior paths at least every 150', so no array section over 150' × 150'

•  between array sections: an 8' path, or a 4' path along 4' × 8' vent cutouts every 20'

Sources (the 2025 code text, free to read on ICC):

•  CRC R329.6 roof access (exemptions)

•  CRC R329.6.1 paths

•  CRC R329.6.2 ridge (R329.6.2.1 with sprinklers)

•  CRC R329.6.3 egress

•  CFC 1205.3 commercial (1205.3.1 edge, 1205.3.2 interior paths, 1205.3.3 between sections)

Written by Claude Code and Mike