Austin setback requirements: front, side, rear and street side
| SF-1 | SF-2 / SF-3 | Duplex / 2–3 unit | Small lot (SF-3+) | |
|---|---|---|---|---|
| Front | 25 ft | 25 ft | 15 ft | 10 ft |
| Street side (corner) | 15 ft | 15 ft | 5–10 ft by street level | 5–10 ft by street level |
| Interior side | 10 ft | 5 ft | base district | 5 ft |
| Rear | 10 ft | 10 ft | base, or 5 ft at an alley | 5 ft |
Base zoning from §25-2-492; multi-unit from §25-2-773(B); small lot from §25-2-779. Inside the Subchapter F boundary the front setback may be reduced further — see below.
The front setback rule almost nobody uses
§2.3 is written as a benefit and reads like a restriction, which is probably why it gets missed. The minimum front yard setback under Subchapter F is the lesser of:
- the minimum prescribed elsewhere in the Code — 25 feet in SF-2 and SF-3; or
- the average front yard setback of the nearby houses, if an average can be determined.
"The lesser of" is the operative phrase. If the houses on your block sit closer to the street than 25 feet, you may sit closer too — and on older Central Austin blocks, many do.
The average is taken from four principal residential structures that are (a) built within fifty feet of the front lot line, and (b) closest to and on the same side of the block as your lot. The fifty-foot filter matters: a house set far back is excluded from the average entirely rather than dragging it upward.
Fewer than four qualifying structures? Use however many there are on your side. None at all? Use the four closest on the opposite side of the block.
The minimum front yard setback required for development subject to this Subchapter is the lesser of: 1. The minimum front yard setback prescribed by the other provisions of this Code; or 2. The average front yard setback, if an average may be determined as provided in Subsection B. below.
What the setback is measured to
§2.3.B.1 is specific: a front yard setback is the distance from the front lot line to the closest front exterior wall or building façade of the principal residential structure.
The wall, not the eave. Not the porch steps, not the bay window. Which matters for the average calculation as much as for your own house — you are comparing wall positions, and a neighbour's deep porch does not pull the average toward the street.
Setbacks are not the same thing as setback planes
Two different controls with confusingly similar names, and both apply at once.
A setback is a line on the ground. Your building must stay behind it.
A setback plane is a sloping surface in the air, rising from the property line at 45 degrees above a 15-foot vertical. Your building must stay under it.
So a house can sit perfectly within its 5-foot side setback and still breach the side setback plane at the second floor. The setback governs where the wall goes; the plane governs how tall it can be once it gets there.
HOME cut these substantially
The base numbers assume one house on a standard lot. If that is not what you are building, the setbacks shrink considerably.
Duplex, two-unit, three-unit (§25-2-773(B)) — front drops from 25 feet to 15. The rear stays at the base district minimum unless the lot backs an alley, or backs another lot zoned multifamily or less restrictive, in which case it drops to five feet.
Small lots (§25-2-779) — front 10 feet on SF-3 or more restrictive, five for a flag lot. Side and rear five feet. On SF-4A or less restrictive the interior side drops to three and a half feet, with the combined width of both interior side yards required to be at least seven feet.
Two provisions go to zero. Where an attached dwelling unit abuts a property line, the setback for that line is zero — that is what makes rowhouses possible. And a side or rear setback may be zero where the lot line is shared with another lot subdivided to under 5,750 sq ft and approved on or after 16 August 2024, so newly created small lots can build to a shared line.
What may project into a setback
On a small lot §25-2-779(F)(6) allows a defined set of projections into a required yard:
- Two feet — windowsill, belt course, cornice, flue, chimney, eave, awning, box window or cantilevered bay window.
- Three feet — a one-storey uncovered porch, stoop or steps.
The three-foot porch allowance is worth designing to. On a lot with a ten-foot front setback it is the difference between a step and something you can actually sit on.
Where we actually use the average
The average front setback is the first thing we check on an older block, because the answer is often four or five feet of extra depth for free — and on a narrow lot depth is what you are short of.
It takes a survey of the block face to establish, so it is worth doing early rather than discovering it after the plan is drawn to 25 feet. The fifty-foot rule is the part people get wrong: a neighbour with a deep front lawn is simply not in the calculation, so a block that looks inconsistent can still average well below the code minimum.
Common questions
Working out what you can build?
We build in Central Austin and deal with this code on every project. If you own a lot and want a straight answer about what fits on it, we're happy to take a look.
Talk to us about your lotWe are homebuilders, not the City of Austin. This page explains how we read the code in practice — it is not legal advice and it is not an official determination. Always confirm with Austin Development Services before you rely on it for a project. The authoritative text is the Austin Land Development Code; permitting questions go to Austin Development Services Department.