The state rule: four conditions, all at once
A deck is exempt from a building permit in California only when every row below is true. Miss one and it needs a permit. Edition: 2025 California Residential Code, which applies to permits applied for on or after January 1, 2026.
- Size 200 sq ft or lessCRC R105.2
- Measured as the deck's area. One square foot over and the exemption is gone.
- Height 30 inches or less above gradeCRC R105.2
- At any point, not on average. On a sloping yard the low corner decides it.
- Attachment not attached to the houseCRC R105.2
- A deck bolted to the house through a ledger board needs a permit at any size.
- Exit door does not serve the required exit doorCRC R105.2, R318.4
- If the deck is the landing outside the door the code counts as the home's exit, it needs a permit whatever its size.
Exempt does not mean anything goes: the same section says an exemption does not allow work that breaks the code, so a small low deck is still built to the same numbers.
Your city: who issues the permit
The building department that issues the permit has the final say, and several of ours add their own steps. Each row links that department's own page. Where a place is unincorporated, the county issues the permit.
- Almaden City of San Joséissues the permit
- San José also requires a permit when the deck serves as a door landing. Building department · Deck handout · County, for unincorporated addresses
- Aptos County of Santa Cruzcounty permit
- Above 18 inches over grade, the county also asks for a site plan for zoning clearance. Building department · Deck handout
- Atherton Town of Athertonissues the permit
- Building department
- Belmont City of Belmontissues the permit
- Building department
- Burlingame City of Burlingameissues the permit
- Above 30 inches over grade, Planning Division approval comes before the building permit. Building department · Deck handout
- Capitola City of Capitolaissues the permit
- The city lists decks “regardless of height” among work that needs a permit. Building department
- Cupertino City of Cupertinoissues the permit
- Building department
- Emerald Hills County of San Mateocounty permit
- Building department · Deck handout
- Foster City City of Foster Cityissues the permit
- Building department
- Gilroy City of Gilroyissues the permit
- Building department
- Half Moon Bay City of Half Moon Bayissues the permit
- Building department
- Hillsborough Town of Hillsboroughissues the permit
- Building department
- Los Altos City of Los Altosissues the permit
- Building department
- Los Altos Hills Town of Los Altos Hillsissues the permit
- Building department
- Los Gatos Town of Los Gatosissues the permit
- The town’s handout: decks under 30 inches above grade, accessory to a dwelling, typically need no permit. Building department · Deck handout
- Menlo Park City of Menlo Parkissues the permit
- Building department
- Milpitas City of Milpitasissues the permit
- Building department
- Montara County of San Mateocounty permit
- Building department · Deck handout
- Monte Sereno City of Monte Serenoissues the permit
- Building department
- Morgan Hill City of Morgan Hillissues the permit
- Building department · Deck handout
- Mountain View City of Mountain Viewissues the permit
- Building department
- Pacifica City of Pacificaissues the permit
- Building department · Deck handout
- Palo Alto City of Palo Altoissues the permit
- The city’s deck handout requires a permit when the deck is over 30 inches above grade, attached to the building, has steps, or is part of the exit path. Building department · Deck handout
- Portola Valley Town of Portola Valleyissues the permit
- The exemption stops at 120 square feet here, not 200. Building department · Source of this rule
- Redwood City City of Redwood Cityissues the permit
- Above 18 inches over grade, Planning Division approval comes before the building permit. Building department · Deck handout
- San Carlos City of San Carlosissues the permit
- “All decks require a permit.” Building department · Deck handout
- San Jose City of San Joséissues the permit
- San José also requires a permit when the deck serves as a door landing. Building department · Deck handout
- San Martin County of Santa Claracounty permit
- Building department
- San Mateo City of San Mateoissues the permit
- Building department
- Santa Cruz City of Santa Cruzissues the permit
- Building department
- Saratoga City of Saratogaissues the permit
- Building department
- Scotts Valley City of Scotts Valleyissues the permit
- Building department
- Sunnyvale City of Sunnyvaleissues the permit
- Building department
Questions people actually ask
Do I need a permit to build a deck in California?
Yes, unless the deck meets all four conditions at once: 200 square feet or less, no more than 30 inches above grade at any point, not attached to the house, and not serving the required exit door (CRC R105.2). Miss any one of them and the deck needs a permit.
What size deck needs a permit?
Anything over 200 square feet. A smaller deck can still need one if it is higher than 30 inches at any point, attached to the house, or serves the exit door.
Do I need a permit to replace deck boards?
Ordinary repairs need no application under CRC R105.2.2, and swapping worn boards is usually treated that way. The same section excludes removing or cutting a structural beam or load-bearing support, so replacing joists, beams or posts is not an ordinary repair. Your building department makes the call.
Does a city's rule differ from the state's?
It can. Cities and counties may amend the state code and add their own reviews. The table on this page links each city's own building department so you can read their version, not ours.
Who pulls the permit, me or the contractor?
Either can, and it should be agreed in writing before work starts. Whoever pulls it, the inspection is against the same code, and an unpermitted deck is the owner's problem at sale time.
Does it cost money to get a deck permit?
Yes — cities charge permit fees, and the amount depends on the city and the project. When a project needs engineering calculations and drawings, those are separate costs as well. Permit management — the applications, coordinating the engineer, and communication with the city and the inspector — is available as a separate service; city fees, engineering and drawings are not included in it.
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