Ione · Land use · Duplex
Where is a duplex allowed in Ione?
In Ione, a duplex is needs a site plan review (administrative or discretionary, per section 17.10.030) in 8 (R-1a, R-1b, R-1c, R-2, R-3 and 3 more, 1 with a condition) and not allowed in 7 (Ione use tables, read October 2026).
Key points
- Needs a permit: R-1a, R-1b, R-1c, R-2, R-3, R-4, C-T and C-2
- Not allowed: A, MP, C-1, C-3, B-P, M-1 and M-2
Find your lot's zone on the city zoning map, then read its row. Every status below was read from the Ione 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
Ione'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.
| Zone | Status | Code |
|---|---|---|
| R-1a One-family Dwelling | Needs a site plan review (administrative or discretionary, per section 17.10.030) | Article II — Zoning Districts, Allowed Uses, and Development Standards |
| R-1b One-family Dwelling | Needs a site plan review (administrative or discretionary, per section 17.10.030) | Article II — Zoning Districts, Allowed Uses, and Development Standards |
| R-1c One-family Dwelling | Needs a site plan review (administrative or discretionary, per section 17.10.030) | Article II — Zoning Districts, Allowed Uses, and Development Standards |
| R-2 Limited Multiple-family Dwelling | Needs a site plan review (administrative or discretionary, per section 17.10.030) | Article II — Zoning Districts, Allowed Uses, and Development Standards |
| R-3 Multiple-family Dwelling | Needs a site plan review (administrative or discretionary, per section 17.10.030) | Article II — Zoning Districts, Allowed Uses, and Development Standards |
| R-4 High Density Multiple-Family Dwelling | Needs a site plan review (administrative or discretionary, per section 17.10.030) | Article II — Zoning Districts, Allowed Uses, and Development Standards |
| C-T Commercial-Transition | Needs a site plan review (administrative or discretionary, per section 17.10.030) | Article II — Zoning Districts, Allowed Uses, and Development Standards |
| C-2 Central Business District Commercial | Needs a site plan review (administrative or discretionary, per section 17.10.030) — see note Note 1: Only allowed as mixed use development as residential in conjunction with and above ground-floor retail, service, or office uses. | Article II — Zoning Districts, Allowed Uses, and Development Standards |
Zones where it is not allowed
What else applies
- Standards for this use: Chapter 17.114 and Chapter 17.118 (named in the Applicable Regulations column; chapter text not in packet).
- "Dwelling, Three- and Four-Family" is a separate row (R-2/R-3/R-4 SP; C-T SP; C-2 SP 1).
- 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: S-P and P-D (special purpose districts) and H overlay: no use table in the text. Table 17.20.020-1 writes the business zone as "BP"; the use tables write "B-P".. Overlay zones and specific plans can also change the answer.
Other uses in Ione
Who this affects
Frequently asked questions
Can I have a duplex in the R-1a zone in Ione?
Only with a site plan review (administrative or discretionary, per section 17.10.030). Ione's use table lists it that way in R-1a (One-family Dwelling) (Article II — Zoning Districts, Allowed Uses, and Development Standards).
Can I have a duplex in the A zone in Ione?
No. Ione's use table does not allow it in A (Agricultural) (Article II — Zoning Districts, Allowed Uses, and Development Standards).
General information, not legal advice.
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