Napa · Zoning · RT 4
Napa RT 4 zoning: height, setbacks and lot size
In Napa's RT 4 zone, buildings can be up to 30 ft (2.5 stories) tall, the front setback is 20 ft and the minimum lot size is 4,000 sq ft (Napa code, read October 2026).
Key points
- Maximum building height: 30 ft
- Maximum number of stories: 2.5 stories
- Minimum front setback: 20 ft
- Minimum side setback: 15 ft (this row is separate from the side-yard rows: 5 ft on one side and 10 ft on the other)
- Minimum rear setback: 20 ft
- Minimum lot size: 4,000 sq ft
- Maximum lot coverage: 50%
RT 4 is a zoning district in Napa. Every value below was read from the Napa Municipal Code and links to its section (read October 2026). State laws such as the ADU and SB 9 rules can allow more on a residential lot. General information, not legal advice — read the code text and check with the city before you build.
Development standards in RT 4
The general rule for a typical lot in this zone. Zoning tables often attach notes, such as rules for corner lots, lots next to a residential zone, or new subdivisions only. Open “code text” under a value to see the table cell or sentence it was read from.
| Maximum building height | 30 ft § 17.08.030 · code textTable row “Height—principal building stories/ height in feet, whichever is more restrictive”, column “RS 4 RI 4 RT 4”: 2.5/30 |
|---|---|
| Maximum number of stories | 2.5 stories § 17.08.030 · code textTable row “Height—principal building stories/ height in feet, whichever is more restrictive”, column “RS 4 RI 4 RT 4”: 2.5/30 |
| Minimum front setback | 20 ft § 17.08.030 · code textTable row “Front Setback (feet)”, column “RS 4 RI 4 RT 4”: 20 |
| Minimum side setback | 15 ft Applies: this row is separate from the side-yard rows: 5 ft on one side and 10 ft on the other § 17.08.030 · code textTable row “Side Setback (feet)”, column “RS 4 RI 4 RT 4”: 15 |
| Minimum rear setback | 20 ft § 17.08.030 · code textTable row “Rear Yard (feet)”, column “RS 4 RI 4 RT 4”: 20 |
| Minimum lot size | 4,000 sq ft § 17.08.030 · code textTable row “Minimum Lot Area (sq. ft.)”, column “RS 4 RI 4 RT 4”: 4,000 |
| Maximum lot coverage | 50% § 17.08.030 · code textTable row “Lot Coverage”, column “RS 4 RI 4 RT 4”: 50% |
When a different number applies
The code sets other values for particular lots, buildings or locations in RT 4:
- Maximum building height: 35 ft — Height may be increased with design review approval. § 17.08.030
- Minimum side setback: 5 ft on one side, 10 ft on the other — 1-story building § 17.08.030
- Minimum side setback: 5 ft on one side, 10 ft on the other — 2 to 2.5 stories; next to an existing 1-story house, the second story must also be set back at least 10 ft § 17.08.030
Not on this page
We did not find a general FAR, density limit for RT 4 in the zoning tables we read. The code may still set one elsewhere — check the Napa Municipal Code.
Other Napa zoning districts
Who this affects
Frequently asked questions
What is the maximum building height in Napa's RT 4 zone?
30 ft — Napa Municipal Code § 17.08.030.
What is the maximum number of stories in Napa's RT 4 zone?
2.5 stories — Napa Municipal Code § 17.08.030.
What is the minimum front setback in Napa's RT 4 zone?
20 ft — Napa Municipal Code § 17.08.030.
What is the minimum side setback in Napa's RT 4 zone?
15 ft (this row is separate from the side-yard rows: 5 ft on one side and 10 ft on the other) — Napa Municipal Code § 17.08.030.
What is the minimum rear setback in Napa's RT 4 zone?
20 ft — Napa Municipal Code § 17.08.030.
General information, not legal advice.
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