Structure Height Limits: San Mateo vs South San Francisco
How do structure height limits rules compare between San Mateo, CA and South San Francisco, CA?
San Mateo and South San Francisco have similar restriction levels.
San Mateo, CA
San Mateo County
San Mateo limits residential building height through Title 27. Single-family zones generally allow 28-35 feet depending on zone. The city applies a daylight plane standard that further limits height near property lines. ADU-specific height limits are 16 feet (detached) to 32 feet (attached) to roof peak.
View full San Mateo rules →South San Francisco, CA
San Mateo County
Residential building height limits in unincorporated San Mateo County are set by district. The Planned Agricultural District caps structures at 3 stories or 36 feet, with a 28-foot limit in the Midcoast area. Public and institutional buildings may reach 75 feet with increased yards.
View full South San Francisco rules →Key Facts Comparison
| Fact | San Mateo | South San Francisco |
|---|---|---|
| R-1 Zone | Generally 28-35 feet | - |
| Detached ADU | 16 ft plateline / 24 ft peak | - |
| Attached ADU | 24 ft plateline / 32 ft peak | - |
| Daylight Plane | Limits height near property lines | - |
| Code Reference | SMMC Title 27 zone standards | - |
| Planned Ag District | - | 3 stories or 36 feet max |
| Midcoast residential | - | 28 feet max |
| Institutional/public | - | Up to 75 ft with increased yards |
| Overall cap | - | 150 ft (except A-1, A-2, M-2) |
| Downhill slope | - | +1 story on downhill side (Sec. 8.336.020) |
| Code basis | - | Zoning Reg. Ch. 8.336 & Sec. 8.106.090 |
Highlighted rows indicate differences between cities.
San Mateo FAQ
What is the maximum building height in San Mateo?
It varies by zone, typically 28 to 35 feet for single-family zones. The daylight plane standard may further limit height near property lines.
What is the daylight plane?
The daylight plane begins at a set height at the property line and angles upward. It limits how tall you can build close to neighbors to prevent overshadowing.
How tall can an ADU be?
Detached ADUs: 16 feet to top plateline, 24 feet to roof peak. Attached ADUs: 24 feet to plateline, 32 feet to peak.
South San Francisco FAQ
How tall can a house be in unincorporated San Mateo County?
It depends on the district. In the Planned Agricultural District the limit is 3 stories or 36 feet, dropping to 28 feet for residential structures in the Midcoast area. Confirm your parcel's specific limit with Planning and Building.
Can I get extra height on a sloped lot?
Yes. Section 8.336.020 allows one additional story on the downhill side where the lot's average slope exceeds a 1-foot rise or fall per 7 feet from street grade, but the building still cannot exceed the district's overall height limit.
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