Fairfax · Zoning · RM
Fairfax RM zoning: height, setbacks and lot size
In Fairfax's RM zone, generally buildings can be up to 28.5 ft (2 stories) tall and the front setback is 10 ft, with the conditions listed below (Fairfax code, read October 2026).
Key points
- Maximum building height: 28.5 ft (Principal-use buildings on lots sloping 10 percent or less; on steeper lots, 35 ft on the downhill side of the street)
- Maximum number of stories: 2 stories (Principal-use buildings on lots sloping 10 percent or less; steeper lots uphill of the street may have three stories)
- Minimum front setback: 10 ft (Slope 10 percent or less; front plus rear yards at least 40 ft (35 ft for affordable density bonus project); garage setback 18 ft)
- Minimum side setback: 10 ft (Slope 10 percent or less; side yards total at least 25 ft (15 ft for affordable density bonus project); garage setback 18 ft)
- Minimum rear setback: 10 ft (Slope 10 percent or less; front plus rear yards at least 40 ft (35 ft for affordable density bonus project); garage setback 18 ft)
RM (Multiple-Family Residential Zone) is a zoning district in Fairfax. Every value below was read from the Fairfax 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 RM
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 | 28.5 ft Applies: Principal-use buildings on lots sloping 10 percent or less; on steeper lots, 35 ft on the downhill side of the street § 17.088.060 · code text(2) On lots having a slope in excess of ten percent, no building or structure occupied by a principal use and situated on the downhill side of the street upon which it has its primary frontage shall exceed 35 feet in height, and if situated on the uphill side of the street shall not exceed 28.5 feet in height nor contain more than three stories. |
|---|---|
| Maximum number of stories | 2 stories Applies: Principal-use buildings on lots sloping 10 percent or less; steeper lots uphill of the street may have three stories § 17.088.060 · code text(2) On lots having a slope in excess of ten percent, no building or structure occupied by a principal use and situated on the downhill side of the street upon which it has its primary frontage shall exceed 35 feet in height, and if situated on the uphill side of the street shall not exceed 28.5 feet in height nor contain more than three stories. |
| Minimum front setback | 10 ft Applies: Slope 10 percent or less; front plus rear yards at least 40 ft (35 ft for affordable density bonus project); garage setback 18 ft § 17.088.070 · code text(A) A front and rear yard having a combined depth of not less than 40 feet, but neither yard having a depth of less than ten feet and a minimum setback for garages of 18 feet. The combined depth may be reduced to 35 feet for an affordable housing project with a density bonus approved under Chapter 17.050. |
| Minimum side setback | 10 ft Applies: Slope 10 percent or less; side yards total at least 25 ft (15 ft for affordable density bonus project); garage setback 18 ft § 17.088.070 · code text(B) Two side yards having a combined width of not less than 25 feet, but neither yard having a width of less than ten feet and a minimum setback for garages of 18 feet. The combined width may be reduced to 15 feet with a minimum interior yard width of five feet for an affordable housing project with a density bonus approved under Chapter 17.050. |
| Minimum rear setback | 10 ft Applies: Slope 10 percent or less; front plus rear yards at least 40 ft (35 ft for affordable density bonus project); garage setback 18 ft § 17.088.070 · code text(A) A front and rear yard having a combined depth of not less than 40 feet, but neither yard having a depth of less than ten feet and a minimum setback for garages of 18 feet. The combined depth may be reduced to 35 feet for an affordable housing project with a density bonus approved under Chapter 17.050. |
When a different number applies
The code sets other values for particular lots, buildings or locations in RM:
- Maximum building height: 36 ft — On lots sloping over 10 percent, may be approved for an affordable housing density bonus project under Chapter 17.050 § 17.088.060
- Maximum number of stories: 1 story — Accessory buildings and structures, which are also limited to 16 ft § 17.088.060
- Minimum side setback: 5 ft — Affordable housing project with a density bonus under Chapter 17.050; the two side yards may total 15 ft § 17.088.070
Not on this page
We did not find a general lot size, lot coverage, FAR, density limit for RM in the zoning tables we read. The code may still set one elsewhere — check the Fairfax Municipal Code.
Other Fairfax zoning districts
Who this affects
Frequently asked questions
What is the maximum building height in Fairfax's RM zone?
28.5 ft (principal-use buildings on lots sloping 10 percent or less; on steeper lots, 35 ft on the downhill side of the street) — Fairfax Municipal Code § 17.088.060.
What is the maximum number of stories in Fairfax's RM zone?
2 stories (principal-use buildings on lots sloping 10 percent or less; steeper lots uphill of the street may have three stories) — Fairfax Municipal Code § 17.088.060.
What is the minimum front setback in Fairfax's RM zone?
10 ft (slope 10 percent or less; front plus rear yards at least 40 ft (35 ft for affordable density bonus project); garage setback 18 ft) — Fairfax Municipal Code § 17.088.070.
What is the minimum side setback in Fairfax's RM zone?
10 ft (slope 10 percent or less; side yards total at least 25 ft (15 ft for affordable density bonus project); garage setback 18 ft) — Fairfax Municipal Code § 17.088.070.
What is the minimum rear setback in Fairfax's RM zone?
10 ft (slope 10 percent or less; front plus rear yards at least 40 ft (35 ft for affordable density bonus project); garage setback 18 ft) — Fairfax Municipal Code § 17.088.070.
General information, not legal advice.
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