Short answer: in nearly every Bay Area city, you do need a demolition permit to remove a detached garage, deck, or shed – even if it looks like a small project. The threshold is typically based on square footage, foundation type, and whether the structure is attached to your home. Skipping the permit can create real problems when you sell.
Here is the city-by-city reality, the rules of thumb that hold across the Bay Area, and the gotchas every homeowner should know before swinging a sledgehammer.
The general rules of thumb
Garages
Almost always require a permit. Detached garages over 120 square feet (the typical threshold) require a demolition permit in every Bay Area city we have worked in. Attached garages always do, regardless of size, because they involve the main structure.
Sheds
Depends on size and foundation. Most cities exempt sheds under 120 square feet on a non-permanent foundation (gravel pad, concrete blocks, dirt). Anything larger, anything on a poured concrete slab, or anything with electrical/plumbing service needs a permit.
Decks
Threshold varies by city, but lower than you think. Most Bay Area cities require permits for decks more than 30 inches above grade, attached to the house, or over 200 square feet. Ground-level patios and small floating decks often do not require a demolition permit.
Pergolas and gazebos
Same rules as sheds – depends on size and whether they are anchored.
Carports and patio covers
Usually require a permit if they are permanent structures attached to the house. Free-standing canopies may not.
Bay Area city specifics
San Francisco
SF DBI requires a permit for almost any detached accessory structure demo. Sheds under 100 square feet on a non-permanent foundation are typically exempt, but everything else needs paperwork.
San Mateo County (Belmont, Redwood City, San Mateo, Palo Alto)
Threshold is generally 120 sq ft for sheds, lower for structures with electrical or plumbing. Decks 30″+ above grade or attached to the house require permits.
Oakland and East Bay
Similar 120 sq ft threshold. Oakland is particularly strict about deck demolition near property lines.
San Jose and South Bay
Permit required for detached structures over 120 sq ft, on a slab, or with utility connections. Smaller wood sheds on gravel often exempt.
Sacramento
Most lenient of the major Bay Area / Northern California cities. Sheds under 200 sq ft typically exempt. Garages and decks still require permits.
Always verify with your specific city’s building department before starting. Rules change.
What happens if you demolish without a permit
- Stop-work order and fines if a neighbor reports the work or an inspector drives by. Common fines: $500-$5,000 plus 2-5x the original permit fee retroactively.
- Disclosure problems when you sell. California’s real estate disclosure requirements mean unpermitted work has to be disclosed. Buyers often demand a retroactive permit or price reduction.
- Insurance complications if any future claim involves the structure or the lot it was on.
- Loan refinancing issues if an appraiser flags missing structures or unexplained slab remnants.
The unexpected costs of “small” demo jobs
Even a small detached garage demolition typically runs $2,500-$6,000 in the Bay Area when done with permits:
- Demolition permit: $200-$800
- Asbestos survey if pre-1981: $500-$1,500
- Utility shutoff (if garage has electrical): $200-$500
- Demolition labor: $1,500-$2,500
- Disposal: $400-$800
- Slab removal (if requested): $800-$2,000 extra
The asbestos catch on older sheds and garages
If your detached garage, shed, or carport is pre-1981, it may contain asbestos siding, roofing felt, or pipe insulation. BAAQMD requires testing before demolition – even for small structures – in the Bay Area. Mavco handles testing and abatement coordination when needed.
What about just removing the deck boards?
If you are only removing the decking material (the top boards) and leaving the framing and foundation in place, most cities consider this maintenance rather than demolition – no permit needed. Removing the framing, posts, and footings is where permits kick in.
The Mavco approach
For accessory structure demos, we pull the right permit, handle any required asbestos testing, coordinate utility shutoffs, demolish, and haul off. A typical detached-garage scope wraps in 1-2 days of work after permitting.
Get a quote for your garage, shed, or deck removal – we will tell you up front whether a permit is required for your specific structure.