San Anselmo · Zoning · R-3
San Anselmo R-3 zoning: height, setbacks and lot size
In San Anselmo's R-3 zone, generally buildings can be up to 30 ft (2 stories) tall, the front setback is 20 ft and the minimum lot size is 7,500 sq ft, with the conditions listed below (San Anselmo code, read October 2026).
Key points
- Maximum building height: 30 ft (Outside Primary and Secondary Ridgezone; on lot with building footprint having an average slope of less than 25%)
- Maximum number of stories: 2 stories (On lot with building footprint having an average slope of less than 25%)
- Minimum front setback: 20 ft
- Minimum side setback: 8 ft (Minimum Interior Side)
- Minimum rear setback: 20 ft
- Minimum lot size: 7,500 sq ft
- Maximum lot coverage: 50% (The town cannot set a coverage limit that blocks a housing project of 8 to 10 units from reaching 1.25 FAR, except on historic sites.)
- Maximum density: 30 units per acre
R-3 is a zoning district in San Anselmo. Every value below was read from the San Anselmo 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 R-3
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 | 30 ft Applies: Outside Primary and Secondary Ridgezone; on lot with building footprint having an average slope of less than 25% § 10-3.402 · code textTable row “On lot with building footprint having an average slope of less than 25%”, column “R-3”: 30' |
|---|---|
| Maximum number of stories | 2 stories Applies: On lot with building footprint having an average slope of less than 25% § 10-3.402 · code textTable row “On lot with building footprint having an average slope of less than 25%”, column “R-3”: 2 |
| Minimum front setback | 20 ft See note 2 below the table in the code. § 10-3.402 · code textTable row “Setback, Minimum Front (2)”, column “R-3”: 20' Note 2: Reference Table 4B of this Chapter for residential projects. |
| Minimum side setback | 8 ft Applies: Minimum Interior Side See note 2 below the table in the code. § 10-3.402 · code textTable row “Minimum Interior Side”, column “R-3”: 8' Note 2: Reference Table 4B of this Chapter for residential projects. |
| Minimum rear setback | 20 ft See note 2 below the table in the code. § 10-3.402 · code textTable row “Setback, Minimum Rear (2)”, column “R-3”: 20' Note 2: Reference Table 4B of this Chapter for residential projects. |
| Minimum lot size | 7,500 sq ft § 10-3.402 · code textTable row “Lot Area, Minimum (Sq. Ft.)”, column “R-3”: 7,500 |
| Maximum lot coverage | 50% Applies: The town cannot set a coverage limit that blocks a housing project of 8 to 10 units from reaching 1.25 FAR, except on historic sites. See note 3 below the table in the code. § 10-3.402 · code textTable row “Lot Coverage, Maximum”, column “R-3”: 50% (3) Note 3: The Town shall not impose a lot coverage requirement that would physically preclude a housing development project with eight to ten units (4) from achieving a Floor Area Ratio of 1.25. However, the 1.25 FAR allowed for housing development projects between 8 to 10 units in this Table 4A shall not apply to a site within a historic district or property included on the State Historic Resources Invento |
| Maximum density | 30 units per acre § 10-3.402 · code textTable row “Density, Maximum (Units/Acre)”, column “R-3”: 30 |
Uses in R-3
Uses the code's use tables allow in R-3, or allow with a permit. Each links to its page with the code section.
- Single-family home — Allowed
- Apartment building — Allowed — see note
- Residential care home (7 or more) — Allowed
- Church or place of worship — Needs a conditional use permit
When a different number applies
The code sets other values for particular lots, buildings or locations in R-3:
- Maximum building height: 35 ft — Outside Primary and Secondary Ridgezone; on lots with building footprint average slope at or greater than 25% § 10-3.402
- Maximum number of stories: 3 stories — On lots with building footprint average slope at or greater than 25% § 10-3.402
- Minimum side setback: 12 ft — Street side yard (the side of a corner lot that faces a street) § 10-3.402
Not on this page
We did not find a general FAR limit for R-3 in the zoning tables we read. The code may still set one elsewhere — check the San Anselmo Municipal Code.
Other San Anselmo zoning districts
Who this affects
Frequently asked questions
What is the maximum building height in San Anselmo's R-3 zone?
30 ft (outside Primary and Secondary Ridgezone; on lot with building footprint having an average slope of less than 25%) — San Anselmo Municipal Code § 10-3.402.
What is the maximum number of stories in San Anselmo's R-3 zone?
2 stories (on lot with building footprint having an average slope of less than 25%) — San Anselmo Municipal Code § 10-3.402.
What is the minimum front setback in San Anselmo's R-3 zone?
20 ft — San Anselmo Municipal Code § 10-3.402.
What is the minimum side setback in San Anselmo's R-3 zone?
8 ft (minimum Interior Side) — San Anselmo Municipal Code § 10-3.402.
What is the minimum rear setback in San Anselmo's R-3 zone?
20 ft — San Anselmo Municipal Code § 10-3.402.
General information, not legal advice.
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