Concord · Land use · Duplex
Where is a duplex allowed in Concord?
In Concord, a duplex is allowed in 3 base zones (RM, CO and CMX, 1 with a condition), needs an administrative permit in 1 (RL, it with a condition) and not allowed in 19 (Concord use tables, read October 2026).
Key points
- Allowed: RM, CO and CMX
- Needs a permit: RL
- Not allowed: RR, RS, RH, NC, SC, RC, DP, DMX and 11 more
Find your lot's zone on the city zoning map, then read its row. Every status below was read from the Concord 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
Concord's code calls this use “Duplex”. 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 |
|---|---|---|
| RM | Allowed — see note Note 2: Prohibited in the affirmatively furthering fair housing overlay district. | § 18.30.020 |
| CO | Allowed | § 18.40.020 |
| CMX | Allowed | § 18.40.020 |
| RL | Needs an administrative permit — see note Note 2: Prohibited in the affirmatively furthering fair housing overlay district. | § 18.30.020 |
Zones where it is not allowed
What else applies
- NTS (North Todos Santos) duplex is 'ZC, MP' (left out, unclear when each applies). Single-family attached is a separate row.
- 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: Zone names for RR, RS, RL, RM, RH, CO, CMX, NC, SC, RC, DP, DMX, WMX, OBP, IBP, IMX, HI, OS, PR, RLC, WRC, CRP-GF (chapter intros not in the packet); Use definitions (CDC 18.20.020) for Group Housing, Residential Care Facility Large, Elementary Middle Secondary; AFFH overlay (Chapter 18.120, S12) is an overlay, not a base zone, and changes SFH, duplex and multifamily rules on listed parcels; Airport overlay (A), other overlays. Overlay zones and specific plans can also change the answer.
Other uses in Concord
Who this affects
Frequently asked questions
Can I have a duplex in the RL zone in Concord?
Only with an administrative permit. Concord's use table lists it that way in RL (§ 18.30.020). The code adds a condition: “Prohibited in the affirmatively furthering fair housing overlay district.”
Can I have a duplex in the RR zone in Concord?
No. Concord's use table does not allow it in RR (§ 18.30.020).
Can I have a duplex in the RM zone in Concord?
Yes, with a condition. Concord's use table lists it as allowed in RM (§ 18.30.020). The code adds a condition: “Prohibited in the affirmatively furthering fair housing overlay district.”
General information, not legal advice.
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