San Carlos · Zoning · RM-20
San Carlos RM-20 zoning: height, setbacks and lot size
In San Carlos's RM-20 zone, generally buildings can be up to 35 ft (3 stories) tall, the front setback is 15 ft and the minimum lot size is 6,000 sq ft, with the conditions listed below (San Carlos code, read October 2026).
Key points
- Maximum building height: 35 ft
- Maximum number of stories: 3 stories
- Minimum front setback: 15 ft (Where 75% or more of lots in a block, both sides of the street, are built: the average of those lots if under 15 ft.)
- Minimum side setback: 5 ft
- Minimum rear setback: 15 ft
- Minimum lot size: 6,000 sq ft (New subdivision lots must follow Table 17.16.030.)
- Maximum lot coverage: 65%
- Maximum floor area ratio (FAR): No maximum FAR (For residential buildings.)
- Maximum density: 20 units per acre
RM-20 (Residential Multifamily District) is a zoning district in San Carlos. Every value below was read from the San Carlos 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 RM-20
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 | 35 ft § 18.04.050 · code textTable row “Maximum Height”, column “RM-20”: 35 ft. |
|---|---|
| Maximum number of stories | 3 stories § 18.04.050 · code textTable row “Maximum Stories”, column “RM-20”: 3 |
| Minimum front setback | 15 ft Applies: Where 75% or more of lots in a block, both sides of the street, are built: the average of those lots if under 15 ft. § 18.04.050 · code textTable row “Front”, column “RM-20”: 15 ft. (C) |
| Minimum side setback | 5 ft § 18.04.050 · code textTable row “Interior Side”, column “RM-20”: 5 ft. (A) |
| Minimum rear setback | 15 ft § 18.04.050 · code textTable row “Rear”, column “RM-20”: 15 ft. |
| Minimum lot size | 6,000 sq ft Applies: New subdivision lots must follow Table 17.16.030. § 18.04.050 · code textTable row “Minimum Lot Size (sq. ft.)”, column “RM-20”: 6,000* |
| Maximum lot coverage | 65% § 18.04.050 · code textTable row “Maximum Lot Coverage (Percent of Lot)”, column “RM-20”: 65% |
| Maximum floor area ratio (FAR) | No maximum FAR Applies: For residential buildings. § 18.04.050 · code textTable row “Maximum Floor Area Ratio (FAR)”, column “RM-20”: No maximum FAR for residential buildings. |
| Maximum density | 20 units per acre § 18.04.050 · code textTable row “Maximum Density (units/net acre)”, column “RM-20”: 20 |
Uses in RM-20
Uses the code's use tables allow in RM-20, or allow with a permit. Each links to its page with the code section.
- Duplex — Allowed
- Apartment building — Allowed
- Residential care home (7 or more) — Needs a minor use permit
- Child care center — Allowed — see note
- Private school — Needs a conditional use permit
Other San Carlos zoning districts
Who this affects
Frequently asked questions
What is the maximum building height in San Carlos's RM-20 zone?
35 ft — San Carlos Municipal Code § 18.04.050.
What is the maximum number of stories in San Carlos's RM-20 zone?
3 stories — San Carlos Municipal Code § 18.04.050.
What is the minimum front setback in San Carlos's RM-20 zone?
15 ft (where 75% or more of lots in a block, both sides of the street, are built: the average of those lots if under 15 ft) — San Carlos Municipal Code § 18.04.050.
What is the minimum side setback in San Carlos's RM-20 zone?
5 ft — San Carlos Municipal Code § 18.04.050.
What is the minimum rear setback in San Carlos's RM-20 zone?
15 ft — San Carlos Municipal Code § 18.04.050.
General information, not legal advice.
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