Very High fire hazard, most of the city
Reporting on CAL FIRE's 2025 Local Responsibility Area maps put Orinda's Very High area at about 5,241 acres, more than any other city in the county (Local News Matters). For homes in those areas, decking within 10 ft of the house is where fire rules bite. New homes must use tested or approved decking there; for replacements, ask the building department and the fire district. What the rules say.
Moraga-Orinda Fire District
Orinda is served by the Moraga-Orinda Fire District (MOFD), which adopts its own ordinances and runs exterior hazard inspections (MOFD ordinances). Read the current ordinances for anything that affects decks, under-deck storage or the area right around the house. MOFD also runs a home hardening grant program; check its current terms if you are hardening the house at the same time.
Steep, wooded lots
Orinda's canyons and dense oak and bay cover mean elevated decks, footings worked around roots, and leaf litter that collects in board gaps and under decks. Wider gaps, clean undersides and an easy way to sweep beneath the deck matter here. Structure details: hillside and elevated decks.
Composite in Orinda
If you want composite near the house, pick a line that is listed for California's wildfire decking tests and ask the builder to show the listing for the exact color and profile. Composite decks · composite vs wood.
Permits
Check with the City of Orinda about who handles plan check and inspection for your address (County building inspection has been reported). Orinda also has a tree ordinance; ask about it before footings go near large oaks. Moraga, next door, uses County building inspection and the same fire district. Deck permits.