Alameda County · Zoning · RMX
Alameda County RMX zoning: height, setbacks and lot size
In Alameda County's RMX zone, generally the front setback is 10 ft and the minimum lot size is 5,000 sq ft, with the conditions listed below (Alameda County code, read October 2026).
Key points
- Minimum front setback: 10 ft (Multi-family buildings; other building types follow the residential design guidelines)
- Minimum side setback: 5 ft (Multi-family buildings; townhomes need no side setback where they share common walls)
- Minimum rear setback: 10 ft (Multi-family buildings; other building types follow the residential design guidelines)
- Minimum lot size: 5,000 sq ft
RMX (Residential mixed density districts) is a zoning district in Alameda County. Every value below was read from the Alameda County 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 RMX
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.
| Minimum front setback | 10 ft Applies: Multi-family buildings; other building types follow the residential design guidelines § 17.51.040 · code textDepth of front yard: Not less than ten feet. |
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| Minimum side setback | 5 ft Applies: Multi-family buildings; townhomes need no side setback where they share common walls § 17.51.040 · code textWidth of side yard: Not less than five feet or ten feet on the street side of a corner lot, or less as required by Section 17.14.080. |
| Minimum rear setback | 10 ft Applies: Multi-family buildings; other building types follow the residential design guidelines § 17.51.040 · code textDepth of rear yard: Not less than ten feet. |
| Minimum lot size | 5,000 sq ft § 17.51.040 · code textEvery use in an RMX district must be on a building site with a median lot width not less than fifty (50) feet and an area not less than five thousand (5,000) square feet. |
When a different number applies
The code sets other values for particular lots, buildings or locations in RMX:
- Minimum side setback: 10 ft — street side of a corner lot § 17.51.040
Not on this page
We did not find a general height, stories, lot coverage, FAR, density limit for RMX in the zoning tables we read. The code may still set one elsewhere — check the Alameda County Municipal Code.
Other Alameda County zoning districts
Who this affects
Frequently asked questions
What is the minimum front setback in Alameda County's RMX zone?
10 ft (multi-family buildings; other building types follow the residential design guidelines) — Alameda County Municipal Code § 17.51.040.
What is the minimum side setback in Alameda County's RMX zone?
5 ft (multi-family buildings; townhomes need no side setback where they share common walls) — Alameda County Municipal Code § 17.51.040.
What is the minimum rear setback in Alameda County's RMX zone?
10 ft (multi-family buildings; other building types follow the residential design guidelines) — Alameda County Municipal Code § 17.51.040.
What is the minimum lot size in Alameda County's RMX zone?
5,000 sq ft — Alameda County Municipal Code § 17.51.040.
General information, not legal advice.
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