El Cajon · Zoning · O-S
El Cajon O-S zoning: height, setbacks and lot size
In El Cajon's O-S zone, generally buildings can be up to 35 ft tall, the front setback is 30 ft and the minimum lot size is 2 acres, with the conditions listed below (El Cajon code, read October 2026).
Key points
- Maximum building height: 35 ft (primary structures)
- Minimum front setback: 30 ft
- Minimum side setback: 15 ft (interior lots)
- Minimum rear setback: 25 ft (an attached carport or covered patio open on two sides, up to 50% of lot width, may be as close as 12 ft)
- Minimum lot size: 2 acres (single-family residence; exclusive of required driveway projections for panhandle or flag lots)
- Maximum lot coverage: 10% (Development other than a PUD; a conditional use permit may allow more)
- Maximum density: 1 unit per 2 acres (single-family development not covered by a planned unit development)
O-S (OPEN SPACE) is a zoning district in El Cajon. Every value below was read from the El Cajon 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 O-S
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 structures § 17.155.120 · code textThe maximum building height is 35 feet for primary structures. |
|---|---|
| Minimum front setback | 30 ft § 17.155.090 · code textEvery lot shall maintain a front yard of not less than 30 feet, with the following exceptions: |
| Minimum side setback | 15 ft Applies: interior lots § 17.155.100 · code textInterior lots shall maintain side yards of not less than 15 feet. |
| Minimum rear setback | 25 ft Applies: an attached carport or covered patio open on two sides, up to 50% of lot width, may be as close as 12 ft § 17.155.110 · code textEvery lot shall maintain a rear yard not less than 25 feet in depth; however, an attached carport or covered patio, open on at least two sides and not greater than 50 percent of the width of the lot, may be constructed; provided such structure is not closer than 12 feet to the rear property line. |
| Minimum lot size | 2 acres Applies: single-family residence; exclusive of required driveway projections for panhandle or flag lots § 17.155.050 · code textThe minimum required lot area for a single-family residence is two acres exclusive of required driveway projections for panhandle or flag lots. |
| Maximum lot coverage | 10% Applies: Development other than a PUD; a conditional use permit may allow more § 17.155.140 · code textAll buildings including accessory buildings and structures, parking areas and driveways and public and private street rights-of-way within the interior of a PUD shall not cover more than 40 percent of the PUD project area. |
| Maximum density | 1 unit per 2 acres Applies: single-family development not covered by a planned unit development § 17.155.080 · code textFor single-family development not covered by a PUD, the density shall be one unit per two acres. |
Uses in O-S
Uses the code's use tables allow in O-S, or allow with a permit. Each links to its page with the code section.
- Single-family home — Allowed
- Growing crops — Allowed
When a different number applies
The code sets other values for particular lots, buildings or locations in O-S:
- Minimum front setback: 20 ft — attached side entrance garage or carport only § 17.155.090
- Minimum front setback: 20 ft — lots facing directly on the arc of a cul-de-sac street; measured on an arc parallel to the front property line § 17.155.090
- Minimum side setback: 20 ft — garage or carport entered directly from the side street § 17.155.100
- Minimum side setback: 10 ft clear width — Lots with no vehicular access to the rear yard from a street or alley; opening must be clear up to 10 ft high § 17.155.100
- Minimum rear setback: 12 ft — attached carport or covered patio open on at least two sides and not greater than 50 percent of lot width § 17.155.110
- Minimum lot size: 5 acres — all other developments, including planned unit developments § 17.155.050
- Maximum lot coverage: 40% — Planned unit development, over the whole PUD project area including parking, driveways and streets § 17.155.140
- Maximum density: 1 unit per acre — planned unit development; all development must be located within a clustered development area that does not exceed 40 percent of total land area § 17.155.080
Not on this page
We did not find a general stories, FAR limit for O-S in the zoning tables we read. The code may still set one elsewhere — check the El Cajon Municipal Code.
Other El Cajon zoning districts
Who this affects
Frequently asked questions
What is the maximum building height in El Cajon's O-S zone?
35 ft (primary structures) — El Cajon Municipal Code § 17.155.120.
What is the minimum front setback in El Cajon's O-S zone?
30 ft — El Cajon Municipal Code § 17.155.090.
What is the minimum side setback in El Cajon's O-S zone?
15 ft (interior lots) — El Cajon Municipal Code § 17.155.100.
What is the minimum rear setback in El Cajon's O-S zone?
25 ft (an attached carport or covered patio open on two sides, up to 50% of lot width, may be as close as 12 ft) — El Cajon Municipal Code § 17.155.110.
What is the minimum lot size in El Cajon's O-S zone?
2 acres (single-family residence; exclusive of required driveway projections for panhandle or flag lots) — El Cajon Municipal Code § 17.155.050.
General information, not legal advice.
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