South San Francisco · Land use · Duplex
Where is a duplex allowed in South San Francisco?
In South San Francisco, a duplex is allowed in 2 base zones (RM-22 and DRL) and not allowed in 7 (South San Francisco use tables, read October 2026).
Key points
- Allowed: RM-22 and DRL
- Not allowed: RL-2.2, RL-8, RH-37.5, RH-50, RH-180, DRM and DRH
Find your lot's zone on the city zoning map, then read its row. Every status below was read from the South San Francisco 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
South San Francisco'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-22 | Allowed | § 20.070.002 |
| DRL Downtown Residential Low | Allowed | § 20.080.002 |
Zones where it is not allowed
What else applies
- 'SB 9 Unit' under Dwelling, Single-Unit (RL-2.2, RL-8 P) restates state law and is not used. Combined headers: 'RH-37.5 and RH-50' is one column (given as two zones); 'BTP-M & GMP' and 'BTP-H & OPSP' are two-district columns (GMP and OPSP are not given as separate cells). PD districts follow their PD Plan (S6).
- 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: PD (Planned Development) districts: S6 sends uses to each PD Plan; Specific Plan districts (S10 is only the Specific Plan chapter); Chapter 20.040 definitions and Chapter 20.350 standards (group residential, community assembly size, day care) are not in the packet. Overlay zones and specific plans can also change the answer.
Other uses in South San Francisco
Who this affects
Frequently asked questions
Can I have a duplex in the RL-2.2 zone in South San Francisco?
No. South San Francisco's use table does not allow it in RL-2.2 (§ 20.070.002).
Can I have a duplex in the RM-22 zone in South San Francisco?
Yes. South San Francisco's use table lists it as allowed in RM-22 (§ 20.070.002).
General information, not legal advice.
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