Selling a house in San Mateo, CA: what the city requires
San Mateo County, California · Last checked November 2026
The City of San Mateo requires a sewer lateral inspection before a sale. The city does not issue a certificate, so proof is the private inspection report.
What San Mateo requires
Sewer lateral inspection at sale (revised Dec. 1, 2020)
- Who does it
- Plumber chosen by the seller.
- Cost
- Contractor inspection. The city has offered 50% cost-sharing grants for repairs in some years.
- Deadline
- Before the sale.
- Applies to
- Sale, improvements of $90,000 or more, and other triggers.
Who to call
San Mateo Public Works
Official page
Housing in San Mateo
- Median year homes were built
- 1965
- Median home value
- $1,618,700
- Owner-occupied homes
- 19,910 of 39,895 (50%)
- Total housing units
- 42,641
Half the homes here were built in 1965 or earlier, so many sewer laterals are 61+ years old and made of clay or cast iron. Older laterals are the ones most likely to fail a test, so budget for a camera inspection before you list.
Source: U.S. Census Bureau, American Community Survey 2020-2024 5-year estimates for San Mateo city, California.
Need this done in San Mateo?
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How the sewer lateral process works
A sewer lateral is the private pipe that carries wastewater from the house to the public sewer main. Many California cities and sanitary districts make sellers prove it does not leak before title can transfer.
- Check whether a valid certificate is already on file for the address. If it is, you may be done.
- Hire a licensed plumber or sewer contractor to video (CCTV) the lateral and, where required, run an air or water pressure test.
- If the lateral fails, the contractor pulls a permit and repairs or replaces it. Many agencies send their own inspector to witness the final test.
- The city or district issues the compliance certificate, and escrow can close.
- If you run out of time, ask about a time extension. These usually require a refundable deposit and a firm deadline after closing.
| Item | Typical range |
|---|---|
| Video inspection or pressure test | $250 to $750 |
| Spot repair | $1,500 to $10,000 |
| Full lateral replacement | $8,000 to $25,000 or more |
Read the full sewer lateral guide
Other towns with the same requirement: Sewer lateral video or dye test
If the house fails
You can repair before closing, use an escrow or extension where the city allows it, let the buyer assume the work for a credit, or sell as-is. Compare the options.
Frequently asked questions
What does San Mateo require before I sell my house?
The City of San Mateo requires a sewer lateral inspection before a sale. The city does not issue a certificate, so proof is the private inspection report.
How much does the sewer lateral inspection at sale cost in San Mateo?
Contractor inspection. The city has offered 50% cost-sharing grants for repairs in some years. Typical related costs: video inspection or pressure test $250 to $750; spot repair $1,500 to $10,000; full lateral replacement $8,000 to $25,000 or more.
What if my house fails?
You can make the repairs before closing, negotiate a credit with the buyer, or sell as-is to a buyer who will handle the work. Ask the municipality whether it allows a buyer to assume the work or an escrow.
Who pays, the buyer or the seller?
The ordinance usually makes the seller responsible for ordering it, but who pays for repairs is negotiable in the purchase agreement.
How old are the homes in San Mateo?
The median home in San Mateo was built in 1965, and the median home value is $1,618,700, according to the Census Bureau's 2020-2024 American Community Survey.
Nearby: San Francisco Bay Area
- Alameda Required at sale
- Albany Required at sale
- Belvedere Required at sale
- Berkeley Required at sale
- Castro Valley Required in some cases
- Hillsborough Required at sale
- Menlo Park No point-of-sale rule
- Millbrae Required at sale
- Pacifica Required at sale
- San Bruno Required in some cases
- San Carlos No point-of-sale rule
- South San Francisco Required at sale
Cite, link or embed this page
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Sources
- Burlingame Properties, The Burlingame, Hillsborough and San Mateo sewer lateral tests
- City of San Mateo, private sewer lateral program
- U.S. Census Bureau, American Community Survey 2020-2024 5-year estimates (tables B25035, B25077, B25003, B25001)
Last checked November 2026. Rules and fees change by ordinance and resolution. Confirm with the municipality before you list. See something out of date? Report a change.