Colusa County · Land use · Duplex
Where is a duplex allowed in Colusa County?
In Colusa County, a duplex is allowed in 4 base zones (R-2, R-3, R-4 and MU) and not allowed in 22 (Colusa County use tables, read October 2026).
Key points
- Allowed: R-2, R-3, R-4 and MU
- Not allowed: F-A, E-A, U-C, U-T, A-T, R-R, R-1, C-1 and 14 more
Find your lot's zone on the city zoning map, then read its row. Every status below was read from the Colusa County Municipal Code use tables (read October 2026). Base zones only. General information, not legal advice — check with the city before you apply.
Zones where a duplex can go
Colusa County's code calls this use “Duplex Home / Duplex Dwelling”. Each row links to the use table it comes from. A zone marked “see note” has a condition in the code, for example upper floors only or a larger lot.
| Zone | Status | Code |
|---|---|---|
| R-2 Residential Two-Family | Allowed Code row: “Duplex Dwelling” | Article 44-2 — ZONING CLASSIFICATIONS, ALLOWED USES, AND DEVELOPMENT STANDARDS |
| R-3 Residential Multiple Family | Allowed Code row: “Duplex Dwelling” | Article 44-2 — ZONING CLASSIFICATIONS, ALLOWED USES, AND DEVELOPMENT STANDARDS |
| R-4 Apartment-Professional | Allowed Code row: “Duplex Dwelling” | Article 44-2 — ZONING CLASSIFICATIONS, ALLOWED USES, AND DEVELOPMENT STANDARDS |
| MU Mixed Use | Allowed Code row: “Duplex Home” | Article 44-2 — ZONING CLASSIFICATIONS, ALLOWED USES, AND DEVELOPMENT STANDARDS |
Zones where it is not allowed
What else applies
- State law: SB 9 (Gov. Code § 65852.21) allows two homes on most single-family lots with a ministerial permit, also where this table says no.
- Not covered here: FMR (Forest Management and Recreation): its column in Table 44-2.60-2 is empty for every row, so no cell is given; PD and EP are overlay zones. Overlay zones and specific plans can also change the answer.
Other uses in Colusa County
Who this affects
Frequently asked questions
Can I have a duplex in the F-A zone in Colusa County?
No. Colusa County's use table does not allow it in F-A (Foothill Agriculture) (Article 44-2 — ZONING CLASSIFICATIONS, ALLOWED USES, AND DEVELOPMENT STANDARDS).
Can I have a duplex in the R-2 zone in Colusa County?
Yes. Colusa County's use table lists it as allowed in R-2 (Residential Two-Family) (Article 44-2 — ZONING CLASSIFICATIONS, ALLOWED USES, AND DEVELOPMENT STANDARDS).
General information, not legal advice.
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