Cost to Build a Deck in Marin County (unincorporated), CA: what the permits say

How much does it cost to build a deck in Marin County?

The usual decks & stairs job filed with Marin County is $50,000, from 149 priced permits, October 2023 through September 2026. Half of jobs were filed for less, half for more. A filed value is what the contractor wrote on the permit, not a quote or the final bill. A decks & stairs permit here usually takes 335 days from issue to final inspection. How long permits take →

What the spread looks like

Approximately, from each firm's own spread: every firm's range of filed values, weighted by its 149 priced permits across 82 firms, pooled into one. Half of Marin County (unincorporated) decks & stairs permits were filed between $30,000 and $75,100.

By home value

Firms split into thirds by the usual value of the homes they work on, with each third's usual filed value weighted by permits. Home values: Marin County assessed land and improvement values from MarinMap parcels (Proposition 13 values, which usually sit well below market value). Under Proposition 13 a home bought decades ago can carry a value far below what it would sell for today, so treat the home-value matching and the price-versus-similar-jobs comparison as rough.

Busiest firms and what they usually charge

Top 10 by permits in the last 12 months. Usual is each firm's middle filed value; middle half is the range its middle half of jobs were filed in; both are shown for firms with 5 or more priced permits. Busy is not the same as careful: pick what you value to build a list.

Why filed values run low or high

• The 10 busiest firms usually file $50,000; the 80 firms with fewer than 10 permits usually file $40,000.
• Firms working on the most expensive third of homes (usual home value $2,067,307 and up) usually file $68,975, against $50,000 for the least expensive third.
• One permit type covers small and large jobs: 1 in 10 decks & stairs permits is filed under $10,000 and 1 in 10 over $202,000, 20 times as much.
• 98.7% of the 151 permits carry a value; the 2 without one are left out of every figure here.

When to schedule a deck build in Marin County

Marin County files the fewest decks & stairs permits in February (40 against an average month of 100) and the most in August (175). If you can choose, ask for quotes in a quiet month. We have no prices by month, so this is about crews' schedules, not a discount. When each trade is busiest in Marin County →

Guides for this trade

• Hiring a deck builder: 5 red flags and 10 questions, checked against deck permits in 17 cities
• Deck vs patio: the permit line, and what deck permits cost in 9 cities
• What can a homeowner do without a permit? Exempt work in 7 cities, and when you can pull your own
• How to check a contractor's license in California

All guides →

Common questions

• How many quotes should I get for a decks & stairs job in Marin County (unincorporated)?At least three. In the permit record the middle half of Marin County (unincorporated) decks & stairs permits were filed between $30,000 and $75,100, so two ordinary jobs can sit 2.5 times apart and both be normal for Marin County (unincorporated). A third quote shows which one is the outlier. Filed values are what contractors wrote on permits, not quotes, so use them to judge the spread, not to price your own job.
• What range is normal for decks & stairs jobs in Marin County (unincorporated)?Half of permits were filed between $30,000 and $75,100; 8 in 10 between $10,000 and $202,000. These are approximate, pooled from each firm's own spread.
• How much do deck builders charge in Marin County?The usual decks & stairs job is filed at $50,000. The 10 firms with the most permits in the last 12 months usually file $50,000, about the same as the usual. See every firm's usual job →
• Why is this different from the per-square-foot prices I see online?Online prices are quoted per square foot. A filed value is one number for the whole job on one permit, often many square feet plus the work around them, and the Marin County file does not record how many each job covered, so we can't turn $50,000 into a price per square foot.
• How much is the decks & stairs permit fee in Marin County?Marin County's published base fee is Uncovered Deck/Patio: $1,060.00 (Marin County Permit Base Fees, read October 2026). These are base fees; the County adds impact fees and taxes, and other approval agencies can charge their own. The fee is separate from the contractor's price.
• Do bigger houses get bigger bills?In the file, yes for the firms: those working on the upper third of homes by value usually file $68,975, the lower third $50,000. That is firms, not single jobs.
• Where does this data come from?Marin County Community Development Agency building permits on homes in unincorporated Marin (the County's open-data permit and inspection files), read October 2026. How the records work in Marin County (unincorporated) →