San Carlos · Land use · Duplex
Where is a duplex allowed in San Carlos?
In San Carlos, a duplex is allowed in 3 base zones (RS-3, RS-6 and RM-20) and not allowed in 2 (San Carlos use tables, read October 2026).
Key points
- Allowed: RS-3, RS-6 and RM-20
- Not allowed: RM-59 and RM-100
Find your lot's zone on the city zoning map, then read its row. Every status below was read from the San Carlos 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
San Carlos'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.
Zones where it is not allowed
What else applies
- Standards for this use: Section 18.04.080, Duplex standards.
- 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): S7 18.10.030, uses follow the PD plan or specific plan; Airport District (table has no shelter row). Overlay zones and specific plans can also change the answer.
Other uses in San Carlos
Who this affects
Frequently asked questions
Can I have a duplex in the RM-59 zone in San Carlos?
No. San Carlos's use table does not allow it in RM-59 (Residential Multifamily District) (§ 18.04.020).
Can I have a duplex in the RS-3 zone in San Carlos?
Yes. San Carlos's use table lists it as allowed in RS-3 (Residential Single-Family District) (§ 18.04.020).
General information, not legal advice.
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