San Bruno · Zoning · MX-R
San Bruno MX-R zoning: height, setbacks and lot size
In San Bruno's MX-R zone, buildings can be up to 50 feet (3 stories) tall and the front setback is 5 feet minimum, 10 feet average (San Bruno code, read October 2026).
Key points
- Maximum building height: 50 feet
- Maximum number of stories: 3 stories
- Minimum front setback: 5 feet minimum, 10 feet average
- Minimum side setback: None required
- Minimum rear setback: None required
- Maximum floor area ratio (FAR): 2.0 (Parcels less than 20,000 sq. ft.)
- Maximum density: 40.0 dwelling units per acre (Projects with city-approved streetscape improvements may get a bonus of up to 8.0 units per acre.)
MX-R is a zoning district in San Bruno. Every value below was read from the San Bruno Municipal Code and links to its section (read October 2026). State laws such as the ADU and SB 9 rules can allow more on a residential lot. General information, not legal advice — read the code text and check with the city before you build.
Development standards in MX-R
The general rule for a typical lot in this zone. Zoning tables often attach notes, such as rules for corner lots, lots next to a residential zone, or new subdivisions only. Open “code text” under a value to see the table cell or sentence it was read from.
| Maximum building height | 50 feet § 12.280.030 · code textTable row “Maximum Height [2]”, column “Height (A)”: 50 feet |
|---|---|
| Maximum number of stories | 3 stories § 12.280.030 · code textTable row “Maximum Stories”, column “Height (A)”: 3 |
| Minimum front setback | 5 feet minimum, 10 feet average § 12.280.030 · code textTable row “Front (B)”, column “Setbacks”: 5 feet minimum, 10 feet average [5,6] |
| Minimum side setback | None required § 12.280.030 · code textTable row “Interior Side”, column “Setbacks”: None |
| Minimum rear setback | None required § 12.280.030 · code textTable row “Rear (C)”, column “Setbacks”: None |
| Maximum floor area ratio (FAR) | 2.0 Applies: Parcels less than 20,000 sq. ft. § 12.280.030 · code textTable row “Parcels less than 20,000 sq. ft.”, column “Maximum FAR”: 2.0 |
| Maximum density | 40.0 dwelling units per acre Applies: Projects with city-approved streetscape improvements may get a bonus of up to 8.0 units per acre. § 12.280.030 · code textTable row “Residential Density”, column “Residential Density”: 40.0 dwelling units per acre [3] |
Uses in MX-R
Uses the code's use tables allow in MX-R, or allow with a permit. Each links to its page with the code section.
- Apartment building — Allowed
When a different number applies
The code sets other values for particular lots, buildings or locations in MX-R:
- Minimum rear setback: 10 feet — If adjacent to R-1 or R-2 District § 12.280.030
- Maximum floor area ratio (FAR): 3.0 — Parcels 20,000 sq. ft. or greater; Residential § 12.280.030
- Maximum floor area ratio (FAR): 0.6 — Parcels 20,000 sq. ft. or greater; Nonresidential § 12.280.030
Not on this page
We did not find a general lot size, lot coverage limit for MX-R in the zoning tables we read. The code may still set one elsewhere — check the San Bruno Municipal Code.
Other San Bruno zoning districts
Who this affects
Frequently asked questions
What is the maximum building height in San Bruno's MX-R zone?
50 feet — San Bruno Municipal Code § 12.280.030.
What is the maximum number of stories in San Bruno's MX-R zone?
3 stories — San Bruno Municipal Code § 12.280.030.
What is the minimum front setback in San Bruno's MX-R zone?
5 feet minimum, 10 feet average — San Bruno Municipal Code § 12.280.030.
What is the minimum side setback in San Bruno's MX-R zone?
None required — San Bruno Municipal Code § 12.280.030.
What is the minimum rear setback in San Bruno's MX-R zone?
None required — San Bruno Municipal Code § 12.280.030.
General information, not legal advice.
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