National City · Zoning · RS-4
National City RS-4 zoning: height, setbacks and lot size
In National City's RS-4 zone, generally buildings can be up to 35 ft (3 stories) tall, the front setback is 10 ft and the minimum lot size is 2,500 sq ft, with the conditions listed below (National City code, read October 2026).
Key points
- Maximum building height: 35 ft (primary structure)
- Maximum number of stories: 3 stories (primary structure)
- Minimum front setback: 10 ft
- Minimum side setback: 3 ft
- Minimum rear setback: 15 ft
- Minimum lot size: 2,500 sq ft
- Maximum density: 1 unit per 2,500 sq ft
RS-4 is a zoning district in National City. Every value below was read from the National City 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 RS-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 | 35 ft Applies: primary structure § 18.21.040 · code textTable row “Maximum height, primary structure”, column “RS-4”: 35' |
|---|---|
| Maximum number of stories | 3 stories Applies: primary structure § 18.21.040 · code textTable row “Maximum stories, primary structure”, column “RS-4”: 3 |
| Minimum front setback | 10 ft See note a below the table in the code. § 18.21.040 · code textTable row “Front”, column “RS-4”: 10'/15(a) Note a: Stoops and porches may extend into the front yard up to the front property line or in the case of a corner parcel, to the side property line. Garages shall maintain a fifteen-foot front yard setback. |
| Minimum side setback | 3 ft See note b below the table in the code. § 18.21.040 · code textTable row “Side—Interior”, column “RS-4”: 3/0(b) Note b: A zero foot minimum side yard, for one side yard on the parcel, is permitted provided that there is a six-foot separation to the adjacent residential structure and that there is a minimum three-foot side yard setback on the opposite side. |
| Minimum rear setback | 15 ft § 18.21.040 · code textTable row “Rear”, column “RS-4”: 15' |
| Minimum lot size | 2,500 sq ft § 18.21.040 · code textTable row “Minimum lot area”, column “RS-4”: 2,500 SF |
| Maximum density | 1 unit per 2,500 sq ft § 18.21.040 · code textTable row “Maximum density”, column “RS-4”: One du for each 2,500 SF of lot area |
When a different number applies
The code sets other values for particular lots, buildings or locations in RS-4:
- Minimum front setback: 15 ft — garages § 18.21.040
- Minimum side setback: 0 ft — one side only, with 6 ft to the adjacent residential structure and at least 3 ft on the opposite side § 18.21.040
Not on this page
We did not find a general lot coverage, FAR limit for RS-4 in the zoning tables we read. The code may still set one elsewhere — check the National City Municipal Code.
Other National City zoning districts
Who this affects
Frequently asked questions
What is the maximum building height in National City's RS-4 zone?
35 ft (primary structure) — National City Municipal Code § 18.21.040.
What is the maximum number of stories in National City's RS-4 zone?
3 stories (primary structure) — National City Municipal Code § 18.21.040.
What is the minimum front setback in National City's RS-4 zone?
10 ft — National City Municipal Code § 18.21.040.
What is the minimum side setback in National City's RS-4 zone?
3 ft — National City Municipal Code § 18.21.040.
What is the minimum rear setback in National City's RS-4 zone?
15 ft — National City Municipal Code § 18.21.040.
General information, not legal advice.
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