Ask three cities whether a deck needs a permit and you'll get three different answers. San Francisco generally requires one for decks above a modest height or attached to the structure; Peninsula cities like Daly City, San Bruno, and San Mateo have their own thresholds. Height, attachment, and structural framing are what matter — not square footage.
Ground-level floating platforms under a certain height are sometimes exempt, but anything with guardrails, stairs, or a ledger attached to the house almost always needs drawings and an inspection. The safe assumption: if it's a real deck, plan on a real permit.
Skipping the permit doesn't just risk a stop-work order. When you sell, unpermitted structures surface in inspection disclosures, and buyers' lenders and insurers get nervous. An approved permit on file is one of the quiet things that protects your home's value.
The process itself is straightforward when it's handled properly: site drawings, an application, plan review, and scheduled inspections at framing and final. ISMA Builders prepares the drawings, files the paperwork, and meets the inspectors as part of every deck build — it's built into the written scope, not billed as a surprise.