Alameda County · Zoning setbacks
Unincorporated Alameda County setback requirements
This table is transcribed from the adopted code and printed on every export with its citation — but the envelope is drawn only after a table passes independent review, and Unincorporated Alameda County’s has not yet. Until it does, the export carries the numbers and says plainly that they are unverified.
The envelope
What the numbers below make on the ground. Shown for the first district in the table; the rest follow the same geometry at their own dimensions.
Zone R-1 — dashed: cited on the export, not yet drawn.
- Front
- 20′
- Side
- 10′
- Rear
- 20′
The hatched band is the yard — ground the code gives up. Drawn not to scale: the yards are proportional to each other, so the deepest one fills the band and the rest follow. The dimensions carry the real numbers, and the export draws them on the actual parcel outline.
Unincorporated Alameda County setbacks by district
Every row is produced by the same function the exporter calls, so this page cannot drift from what the drawing gets. The citation under each row is what prints on the sheet.
Corner lots: 10′ on the secondary street frontage.
Alameda County Ordinance Code §17.08.070 (R-1 / R-2): front 20, side 10, street side 10, rear 20. LOT WIDTH UNKNOWN: the side yard is 5 ft plus 1 ft per full 10 ft of median width over 50 ft (max 10); the 10 ft cap is drawn. UNINCORPORATED Alameda County (Castro Valley, San Lorenzo, Ashland, Cherryland, Fairview, Sunol) — NOT the City of Alameda, which is a separate jurisdiction. General yard provisions (§17.52.330) and permitted projections are not captured and may modify. R-1 and R-2 may reduce the rear yard to 10 ft where the shortfall is COMPENSATED by open area elsewhere on the site (§17.08.080) — a design choice, not a property of the parcel, so the full 20 ft is drawn. No dwelling may open its front or living-room entrance into a side yard under 10 ft (§17.08.090/§17.10.060). Development in the Castro Valley Urbanized Area is additionally subject to the Residential Design Standards and Guidelines for the Unincorporated Communities of West Alameda County, and Castro Valley has a floor-area ratio schedule (§17.08.110). Alameda County Ordinance Code Title 17, print 2026-08-19. Verify with Alameda County Planning.
Corner lots: 10′ on the secondary street frontage.
Alameda County Ordinance Code §17.12.070 (R-S Suburban Residence): front 20, side 10, street side 10, rear 20. LOT AREA UNKNOWN: §17.12.090 substitutes the narrower R-1 side yard where the site permits two dwellings or fewer (under 15,000 sq ft); the R-S 10 ft is drawn. UNINCORPORATED Alameda County (Castro Valley, San Lorenzo, Ashland, Cherryland, Fairview, Sunol) — NOT the City of Alameda, which is a separate jurisdiction. General yard provisions (§17.52.330) and permitted projections are not captured and may modify. R-1 and R-2 may reduce the rear yard to 10 ft where the shortfall is COMPENSATED by open area elsewhere on the site (§17.08.080) — a design choice, not a property of the parcel, so the full 20 ft is drawn. No dwelling may open its front or living-room entrance into a side yard under 10 ft (§17.08.090/§17.10.060). Development in the Castro Valley Urbanized Area is additionally subject to the Residential Design Standards and Guidelines for the Unincorporated Communities of West Alameda County, and Castro Valley has a floor-area ratio schedule (§17.08.110). Alameda County Ordinance Code Title 17, print 2026-08-19. Verify with Alameda County Planning.
Corner lots: 10′ on the secondary street frontage.
Alameda County Ordinance Code §17.06.070 (A Agricultural): front 30, side 10, street side 10, rear 10. Minimum building site in the A district is 100 acres (§17.06.060). UNINCORPORATED Alameda County (Castro Valley, San Lorenzo, Ashland, Cherryland, Fairview, Sunol) — NOT the City of Alameda, which is a separate jurisdiction. General yard provisions (§17.52.330) and permitted projections are not captured and may modify. R-1 and R-2 may reduce the rear yard to 10 ft where the shortfall is COMPENSATED by open area elsewhere on the site (§17.08.080) — a design choice, not a property of the parcel, so the full 20 ft is drawn. No dwelling may open its front or living-room entrance into a side yard under 10 ft (§17.08.090/§17.10.060). Development in the Castro Valley Urbanized Area is additionally subject to the Residential Design Standards and Guidelines for the Unincorporated Communities of West Alameda County, and Castro Valley has a floor-area ratio schedule (§17.08.110). Alameda County Ordinance Code Title 17, print 2026-08-19. Verify with Alameda County Planning.
Setbacks are one layer of a Unincorporated Alameda County site plan
The same address search returns the parcel boundary, 1–2 ft contours, building footprints, CAL FIRE defensible-space zones, the soil profile, four-season sun, and a native plant palette matched to the site. See everything Lekua resolves in Alameda County→
Unincorporated Alameda County setback FAQ
What are the residential setbacks in Unincorporated Alameda County?
In R-1 the code sets a 20 ft front yard, 10 ft sides, and a 20 ft rear yard. The full table is below, transcribed from Alameda County Ordinance Code §17.08.070 with the citation attached to every row. This table is captured and cited on the export, but it has not yet passed independent review — so Lekua prints the code-cited values with an explicit “unverified” advisory rather than drawing lines it can’t stand behind.
Does Lekua draw the setback envelope for Unincorporated Alameda County?
Not yet. The table is encoded and every export carries the code-cited numbers and the citation, but the envelope is only drawn once a table passes independent review. Until then the export says so in plain words instead of drawing a line that might be wrong.
Where do these Unincorporated Alameda County setback numbers come from?
They are transcribed from the adopted code — Alameda County Ordinance Code §17.08.070 — and this page renders them by calling the same function the exporter calls, so what you see here is what the drawing gets. Zoning changes; verify against the current code and with the planning department before submittal.
Can I get a CAD base map for a Unincorporated Alameda County parcel?
Yes. Enter any Unincorporated Alameda County address and Lekua returns a layered DXF base plan and a PDF site report — property lines, 1–2 ft contours, building footprints, CAL FIRE defensible-space zones, soil, seasonal sun, and a native plant palette matched to the parcel, alongside the zoning determination. See what else resolves in Alameda County.
Start with a Unincorporated Alameda County address
Free to search. The zone resolves from the parcel, not from the mailing address.