Los Altos · Zoning · R3-4.5
Los Altos R3-4.5 zoning: height, setbacks and lot size
In Los Altos's R3-4.5 zone, generally buildings can be up to 36 ft (3 stories) tall and the front setback is 20 ft, with the conditions listed below (Los Altos code, read October 2026).
Key points
- Maximum building height: 36 ft
- Maximum number of stories: 3 stories
- Minimum front setback: 20 ft (Property line abutting Homestead Road, Stevens Place or Marshall Court frontage)
- Minimum side setback: 5 ft (Other interior property line not listed above; first story)
- Maximum lot coverage: 60%
- Maximum floor area ratio (FAR): 55%
R3-4.5 (R3-4.5 MULTIPLE-FAMILY DISTRICT) is a zoning district in Los Altos. Every value below was read from the Los Altos 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 R3-4.5
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 | 36 ft § 14.16.090 · code textNo structure shall exceed three stories or thirty-six (36) feet in height as measured from the existing natural grade immediately adjacent to the proposed structure. |
|---|---|
| Maximum number of stories | 3 stories § 14.16.090 · code textNo structure shall exceed three stories or thirty-six (36) feet in height as measured from the existing natural grade immediately adjacent to the proposed structure. |
| Minimum front setback | 20 ft Applies: Property line abutting Homestead Road, Stevens Place or Marshall Court frontage § 14.16.080 · code textTable row “Property line abutting Homestead Road, Stevens Place or Marshall Court frontage”, column “20 feet”: 20 feet |
| Minimum side setback | 5 ft Applies: Other interior property line not listed above; first story § 14.16.080 · code textTable row “First story”: 5 feet |
| Maximum lot coverage | 60% § 14.16.050 · code textThe maximum coverage for all structures in excess of six feet in height shall be sixty (60) percent of the total gross site area. |
| Maximum floor area ratio (FAR) | 55% § 14.16.060 · code textThe maximum floor area shall be fifty-five (55) percent of the gross lot area. |
When a different number applies
The code sets other values for particular lots, buildings or locations in R3-4.5:
- Minimum side setback: 10 ft — Other interior property line not listed above; second story § 14.16.080
Not on this page
We did not find a general rear setback, lot size, density limit for R3-4.5 in the zoning tables we read. The code may still set one elsewhere — check the Los Altos Municipal Code.
Other Los Altos zoning districts
Who this affects
Frequently asked questions
What is the maximum building height in Los Altos's R3-4.5 zone?
36 ft — Los Altos Municipal Code § 14.16.090.
What is the maximum number of stories in Los Altos's R3-4.5 zone?
3 stories — Los Altos Municipal Code § 14.16.090.
What is the minimum front setback in Los Altos's R3-4.5 zone?
20 ft (property line abutting Homestead Road, Stevens Place or Marshall Court frontage) — Los Altos Municipal Code § 14.16.080.
What is the minimum side setback in Los Altos's R3-4.5 zone?
5 ft (other interior property line not listed above; first story) — Los Altos Municipal Code § 14.16.080.
What is the maximum lot coverage in Los Altos's R3-4.5 zone?
60% — Los Altos Municipal Code § 14.16.050.
General information, not legal advice.
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