You have the drawings back from your designer, and the new front room reaches almost to the sidewalk. Your neighbor on the left has a small planted strip in front of their bay window. The one on the right sits right up at the line. Then the planner's comment arrives: what is the required front setback? In most San Francisco residential districts, the honest answer is that your neighbors already decided it.
In the city's RH, RTO and RM districts, your required front setback equals the depth of the adjacent building with the shortest front setback. With only one adjacent building, you must provide half of that building's setback. The requirement is capped at 10 feet, or 15 feet on blocks where deep setbacks dominate (§ 132).
A "front setback" here is simply the strip of your lot, along the street or alley, that has to stay clear of the building. San Francisco calls it a setback rather than a front yard because the rule is about relating your wall to the walls beside it, not about giving you a lawn.
Key numbers
| What | Requirement | Source |
|---|---|---|
| Both neighbors set back | Match the shorter of the two neighboring setbacks | § 132(a) |
| Only one adjacent building | One-half of that building's front setback | § 132(a) |
| Maximum required setback | 10 feet from the property line | § 132(d) |
| Maximum on deep-setback blocks | 15 feet | § 132(d) |
| Gap that still counts as "adjacent" | Up to 50 feet of undeveloped lots | § 132(a) |
| Planted area required | At least 20% of the required setback, unpaved | § 132(g) |
| Permeable area required | At least 50% of the setback area | § 132(h) |
How the depth is measured
The Planning Code measures each neighboring building's setback as the horizontal distance from the property line along the street or alley to the building wall closest to that line. Projections from the wall, decks, garage structures and extensions, and other obstructions are all excluded from that measurement (§ 132(b)).
That matters more than it sounds. A neighbor whose bay window pushes out toward the sidewalk still has whatever setback their actual wall has. You measure the wall, not the bump-outs.
The 10-foot ceiling, and the one exception
The maximum required front setback in any of the cases described in this Section 132 shall be 10 feet from the property line along the Street or Alley (§ 132(d)).
So even where a neighbor sits far back from a wide street, the most the city can require of you under this rule is 10 feet. The exception runs the other way: where more than 75% of the properties on your block face have a setback of 15 feet or more, and both parcels next to yours have 15 feet or more, the ceiling rises to 15 feet (§ 132(d)).
Corner lots, alleys and odd neighbors
Several common San Francisco lot situations have their own rule (§ 132(c)):
- Corner lots and lots at the intersection of a street and an alley, or two alleys, need a front setback along only one frontage — the one the owner elects as the front. Along that frontage the requirement is one-half the adjacent building's setback.
- If the lot next to you fronts on a different street or alley, you disregard it, and your requirement comes from the adjacent building on your other side.
- If the lot next to you is in a commercial, industrial or public district (RC, C, M or P), you disregard that too, and take your setback from the adjacent building that is in the residential district.
- An undeveloped lot between you and the nearest building does not automatically break the chain: if the separation is 50 feet or less, that nearer building still counts as "adjacent."
What is allowed to sit in the setback
Only the obstructions listed separately in the code may occupy a required front setback, and nothing else may be built, placed or maintained there (§ 132(f)). Two of the common ones: architectural projections such as cornices, eaves and sills may extend up to 4 feet into a setback if they leave at least 7½ feet of clearance, and bay windows and balconies may project 3 feet with the same minimum headroom (§ 136(c)).
One rule surprises people: you may not park a car, trailer or boat in a required front setback area, except as the obstruction rules specifically allow (§ 132(f)).
Landscaping and drainage come with it
The setback is not just empty ground. At least 20% of the required setback area must remain unpaved and planted, and the area must be at least 50% permeable so stormwater can soak in (§ 132(g), § 132(h)). Turf pavers and similar planted hardscapes count toward permeability only, not toward the landscaping share.
These obligations are triggered by a defined list of work: a new building, a new dwelling unit, a garage or added parking, any addition increasing existing gross floor area by 20% or more, a residential merger, or paving or repaving more than 200 square feet of the front setback (§ 132(g)). Where permitted obstructions swallow the entire setback, the Zoning Administrator may accept compliant sidewalk landscaping instead, with a Public Works permit.
Where this rule does not reach
This is a residential-district rule. Downtown C-3 districts are governed by their own setback and streetwall provisions, which work on the upper parts of buildings abutting a public sidewalk rather than on a ground-level front strip (§ 132.1). Your rear yard is a separate calculation under a different section (§ 134), and lots in the Bernal Heights Special Use District take their required setback from a different part of the Planning Code entirely.
Before you draw anything, get your neighbors' actual wall-to-property-line distances measured. In San Francisco that measurement, not a number in a zoning table, is usually what decides your front wall. Our San Francisco code overview is a good next stop for the rest of the dimensional rules.
Sources
- San Francisco Planning Code § 132 — Front setback areas in RTO, RH and RM districts
- San Francisco Planning Code § 136 — Permitted obstructions in required setbacks
- San Francisco Planning Code § 134 — Rear yards
- San Francisco Planning Code § 132.1 — Setbacks and streetwall articulation, C-3 districts
