Building codes & construction
CBC Chapter 7A
The CBC chapter requiring ignition-resistant exteriors — ember-resistant vents, protected glazing, rated siding and decking — in mapped fire hazard zones.
Definition
Chapter 7A of the California Building Code — "Materials and Construction Methods for Exterior Wildfire Exposure" — is the hardened-construction chapter that applies to buildings in mapped fire hazard severity zones (the Residential Code carries parallel provisions for dwellings). It regulates the ignition paths embers actually exploit: vents must resist ember intrusion, exterior glazing needs multiple panes with tempered glass, and roofing, exterior wall coverings, decking and eaves must be noncombustible or ignition-resistant, generally using assemblies and products listed for WUI service. The 2025 cycle pairs it with the new Wildland-Urban Interface Code (Part 7.5).
Why it matters in an underwrite
Where Chapter 7A applies it is not optional and not value-engineerable in the usual way — substitutions must carry WUI listings, which narrows the product universe and raises the envelope budget (vents, windows, cladding and decks are the recurring adds). Whether it applies at all is a map question, so identical plans can price differently across a zone boundary; confirm the parcel's zone before locking an exterior specification.
Sources & related guides
See also
See the term in the law itself
Read the controlling text in the Code Library, or ask the AI how it applies to your project.
Last reviewed 2026-07-29. General information, not legal advice.