Where is a duplex allowed in Sonoma County?

Find your lot's zone on the city zoning map, then read its row. Every status below was read from the Sonoma County Municipal Code use tables (read October 2026). Base zones only. General information, not legal advice — check with the city before you apply.

Sonoma County's code calls this use “Dwelling, Two-Family”. 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.

AR, RR, R1.

• Standards for this use: Use regulations 26-24-090 (text not in packet).
• 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: Chapter 26C coastal districts (LIA CC, LEA CC, DA CC, RRD CC, TP, AR CC, RR, R1, R2, PC, CS, CT, C2, AS, CF, PF): use lists are prose, not tables, and are not mapped here; Definitions and use-regulation sections 26-18 through 26-30 and 26-88 are not in the packet; Combining districts (S, AH, RE, LG, RC, OAK, VOH, G, MR, WH, Z, VR, TS) skipped. Overlay zones and specific plans can also change the answer.

• Single-family home
• Emergency shelter