Blog > Homes With an ADU in San Mateo: Prices, Neighborhoods and Homes for Sale (2026)
Homes With an ADU in San Mateo: Prices, Neighborhoods and Homes for Sale (2026)
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Looking for homes with an ADU in San Mateo? Of the 1,009 houses that sold in San Mateo in the two years to October 27, 2026, 82 (8%) were described in their listings as having an ADU, in-law unit or guest house; across Silicon Valley it’s 9%. Here’s what they sold for, by size, price and neighborhood, and a one-click search of the ones for sale now.
The short answer
- Median price: $2.04M (all San Mateo houses: $2.15M), 2% less per square foot than the typical San Mateo house.
- Typical size: 1,775 sq ft, 3 bedrooms.
- Bidding: 74% sold over asking (all San Mateo houses: 72%).
- Where they sold most: North Central & San Mateo Heights (15), Beresford & Hillsdale (13) and Shoreview & Parkside (12).
Shopping now?
- See homes with an ADU for sale in San Mateo now: our Feature Finder reads every live listing’s description and opens on this search.
- Search all homes for sale, then use Save Search to get new listings by email.
- Talk to a Property Nerd about the streets you’re weighing.
By bedrooms
Homes with an ADU sold in San Mateo in the two years, by bedroom count (groups with at least 3 sales).
| Bedrooms | Sales | Median price | Median sq ft |
|---|---|---|---|
| 2 | 10 | $1.43M | 1,150 |
| 3 | 41 | $1.8M | 1,550 |
| 4 | 16 | $2.42M | 2,080 |
| 5+ | 15 | $3M | 2,773 |
By price
How the 82 sales spread across price bands.
| Sale price | Sales | Share |
|---|---|---|
| under $1M | 1 | 1% |
| $1M to $1.5M | 15 | 18% |
| $1.5M to $2M | 23 | 28% |
| $2M to $2.5M | 14 | 17% |
| $2.5M to $3M | 11 | 13% |
| $3M to $4M | 13 | 16% |
| $4M to $5M | 3 | 4% |
| $5M and up | 2 | 2% |
By neighborhood
Our San Mateo neighborhood guides with at least 3 such sales, placed by map position; “share” is of all house sales in the neighborhood.
| Neighborhood | Sales | Share | Median price |
|---|---|---|---|
| North Central & San Mateo Heights | 15 | 30% | $1.68M |
| Beresford & Hillsdale | 13 | 7% | $2.67M |
| Shoreview & Parkside | 12 | 8% | $1.35M |
| Sunnybrae & 19th Avenue Park | 7 | 10% | $1.9M |
| Baywood & Aragon | 6 | 5% | $3.33M |
| Downtown & Central | 6 | 21% | $1.94M |
| Hayward Park & Glazenwood | 5 | 29% | $3.15M |
| San Mateo Village & Lauriedale | 5 | 7% | $1.7M |
| San Mateo Park | 3 | 6% | $6.55M |
Before you buy
- Ask whether the ADU is permitted. An unpermitted unit can’t be counted on for rent, financing or insurance the same way.
- Check the utilities: separate meters, address and parking.
- Room to build one instead? Many listings only mention the potential; our ADU guide walks through what a lot can hold.
How we counted
Closed sales of houses (MLS property type “single family home”) with a San Mateo address between October 28, 2024 and October 27, 2026, reported to the MLS and read through the IDX feeds that power our home search, with repeat records from different feeds removed (normalized address plus sale date). A house counts when its listing description says so. Price per square foot uses sales with 400 sq ft or more and is compared with the median for all San Mateo houses. Neighborhoods are our guides’ outlines, placed by each sale’s map position. Past sales aren’t a forecast or the value of any one home.
Go deeper
Homes with an ADU across Silicon Valley, every home type in San Mateo, San Mateo neighborhoods compared and the neighborhoods with the most single-story homes, pools and ADUs.
Looking for homes with an ADU in San Mateo?
A Property Nerd will tell you which streets have them, what the recent ones sold for, and set up a search that catches new listings the day they hit. Call (408) 373-1660 or (650) 383-8606, or book a strategy call. Commissions are negotiable, and we offer bundled services, so ask us what’s included.