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

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

The usual pool & spa job filed with Marin County is $70,000, from 155 priced permits, October 2023 through September 2026. The middle half of firms usually file between $35,275 and $122,000. 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 pool & spa permit here usually takes 466 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 155 priced permits across 82 firms, pooled into one. Half of Marin County (unincorporated) pool & spa permits were filed between $32,700 and $138,000.

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 $38,000; the 80 firms with fewer than 10 permits usually file $98,500.
• Firms working on the most expensive third of homes (usual home value $3,210,378 and up) usually file $147,500, against $38,000 for the least expensive third.
• One permit type covers small and large jobs: 1 in 10 pool & spa permits is filed under $15,800 and 1 in 10 over $230,000, 15 times as much.
• 100.0% of the 155 permits carry a value; the 0 without one are left out of every figure here.

When to schedule a pool build in Marin County

Marin County files the fewest pool & spa permits in March (70 against an average month of 100) and the most in October (163). 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

• Questions to ask a pool builder, and how to check the answers against the permit record
• How to verify a contractor: license, permit history and insurance in 24 states
• How to check a contractor's permit history: search by name in 52 cities
• How to check a contractor's license in California

All guides →

Common questions

• How many quotes should I get for a pool & spa job in Marin County (unincorporated)?At least three. In the permit record the middle half of Marin County (unincorporated) pool & spa firms usually file between $35,275 and $122,000 a job, so two ordinary firms can sit 3.5 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 pool & spa jobs in Marin County (unincorporated)?Half of permits were filed between $32,700 and $138,000; 8 in 10 between $15,800 and $230,000. These are approximate, pooled from each firm's own spread.
• How much do pool builders charge in Marin County?The usual pool & spa job is filed at $70,000; the middle half of firms usually file between $35,275 and $122,000. The 10 firms with the most permits in the last 12 months usually file $38,000, less than the usual. See every firm's usual job →
• Why do prices I see online differ from $70,000?$70,000 is the construction value contractors wrote on Marin County permits. Online figures are usually all-in ranges whose scope you can't check (design, fees, site work), and our file mixes small and large jobs of this type in one number. Use the spread above to see where a quote sits.
• How much is the pool & spa permit fee in Marin County?Marin County's published base fee is Structural Pool/spa/Hot Tub: $2,634.00 (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 $147,500, the lower third $38,000. 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) →