Aging 1980s redwood decks
Original decks from the 1980s building boom are reaching the end of their life: checked and splintering boards, rusted fasteners, posts set in soil, and ledgers that were never flashed. Replacement usually means a new frame as well as new boards. Deck replacement.
Composite upgrades
For large decks that get full afternoon sun, color matters: lighter composite stays more comfortable underfoot, and a shade structure helps. If the old frame stays, it must be sound and spaced for the new boards. Composite decks.
Fire hazard maps
Danville has Very High areas on the 2025 maps (2025 reporting). Check your address with the San Ramon Valley Fire Protection District, which serves Danville, Alamo, Blackhawk and Diablo. Fire-resistant decking.
Permits: Town vs County
Inside Danville, the Town's Building Division issues deck permits (Danville Permit Center). Alamo, Blackhawk and Diablo are unincorporated, so permits come from Contra Costa County (County permit overview).
HOA approvals
Blackhawk requires an architectural review application for exterior changes; Diablo has its own property owners association; many Danville subdivisions have CC&Rs too. Get approval before the permit submission.
Protected trees
Danville protects 12 native species from 10 in diameter and any tree 36 in or larger (Danville tree rules). In Alamo and other County areas, native trees from 48 in in circumference are protected. Plan footings around them.
Budgeting a large deck? See the deck cost guide.