Walnut R-3 zoning: height, setbacks and lot size

R-3 (Multiple Family Residential Zone) is a zoning district in Walnut. Every value below was read from the Walnut 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 R-3

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: Main building § 6.32.050 · code text The maximum building or structural height of the main building shall be two stories, or 35 feet, whichever is the lesser, and one story, or 15 feet whichever is the lesser, for accessory buildings.
Maximum number of stories	2 stories Applies: Main building § 6.32.050 · code text The maximum building or structural height of the main building shall be two stories, or 35 feet, whichever is the lesser, and one story, or 15 feet whichever is the lesser, for accessory buildings.
Minimum front setback	20 ft § 6.32.060 · code text Each lot in the R-3 zone shall have a front yard extending, except for access drives and walks, across the full width of the subject property of a depth of not less than 20 feet.
Minimum side setback	5 ft § 6.32.060 · code text There shall be a side yard on each side of the lot extending from the front yard to the rear yard not less than five feet in width.
Minimum rear setback	20 ft § 6.32.060 · code text Each lot shall have a rear yard extending, except for access drives and walks, across the full width of the lot of a depth of not less than 20 feet.
Minimum lot size	9,000 sq ft § 6.32.040 · code text The minimum lot area shall be 9,000 square feet.
Maximum lot coverage	60% Applies: semi-enclosed open-use patio structures and swimming pools are not counted § 6.32.070 · code text The maximum coverage of the lot in an R-3 zone by all structures shall not exceed 60% of the lot building area; provided, that any semi-enclosed patio structure which is used solely for general open use shall not be counted as a structure in ascertaining coverage, nor shall swimming pools be counted.
Maximum density	1 unit per 3,000 sq ft § 6.32.040 · code text C. Minimum lot area per dwelling unit: 3,000 square feet per dwelling unit.

When a different number applies

The code sets other values for particular lots, buildings or locations in R-3:

Minimum side setback: 10 ft — Corner lot; side yard abutting the street § 6.32.060

Not on this page

We did not find a general FAR limit for R-3 in the zoning tables we read. The code may still set one elsewhere — check the Walnut Municipal Code.

Other Walnut zoning districts

Who this affects

HomeownersArchitects and designersDevelopersReal estate agents

Frequently asked questions

What is the maximum building height in Walnut's R-3 zone?

35 ft (main building) — Walnut Municipal Code § 6.32.050.

What is the maximum number of stories in Walnut's R-3 zone?

2 stories (main building) — Walnut Municipal Code § 6.32.050.

What is the minimum front setback in Walnut's R-3 zone?

20 ft — Walnut Municipal Code § 6.32.060.

What is the minimum side setback in Walnut's R-3 zone?

5 ft — Walnut Municipal Code § 6.32.060.

What is the minimum rear setback in Walnut's R-3 zone?

20 ft — Walnut Municipal Code § 6.32.060.

General information, not legal advice.