Austin single-family attached and townhouses: two use types, different rules

Last verified August 7, 2026 against the Austin Land Development Code · Kimbrough Gray · KiliGray Homes

Single-family attached use supersedes the base district: 7,000 sq ft minimum site, 3,000 sq ft minimum lot, 25 ft lot width, one unit per lot and two attached units per site. Townhouses need 20 ft of lot width, 3,600 sq ft of site area each, and at least two connected.

Applies to: Single-family attached residential use and townhouse use. Both modify base district regulations rather than sitting alongside them.

Single-family attached replaces the base district

§25-2-772(A) does something unusual: for a single-family attached residential use, the base zoning district regulations are superseded by that section. Not supplemented — replaced.

So the numbers that govern are its own:

minimum site area — 7,000 sq ft;
minimum lot area — 3,000 sq ft;
minimum lot width, measured for 25 ft back from the front property line — 25 ft, or 20 ft on a cul-de-sac or curved street;
not more than one dwelling unit per lot; and
a site must contain two attached dwelling units.

Against an SF-3 minimum lot size of 5,750 sq ft, a 3,000 sq ft lot is a substantial change — which is the point of the use type.

Site and lot are different things here, and the difference is the whole section. Two 3,000 sq ft lots do not make a compliant project on their own — the site they sit within must be at least 7,000 sq ft. Reading "3,000" as the only number produces a scheme that cannot be built.

Townhouses work on different arithmetic

§25-2-775 does not set a minimum lot area at all. It sets a site area per townhouse:

not more than one townhouse per townhouse lot;
minimum lot width 20 ft;
at least 3,600 sq ft of site area for each townhouse; and
at least two connected townhouses on a site.

Each lot must also include a private yard meeting the zoning district's open space requirement.

	Single-family attached	Townhouse
Section	§25-2-772	§25-2-775
Minimum site	7,000 sq ft	3,600 sq ft per townhouse
Minimum lot	3,000 sq ft	not stated
Lot width	25 ft (20 ft on a curve)	20 ft
Units required	two attached	at least two connected
Private yard	not stated	required

Note the different units. §25-2-772 states a site minimum and a lot minimum; §25-2-775 states site area per townhouse and no lot minimum.

The townhouse driveway limits

Two constraints that shape the street frontage, and both are proportional rather than absolute:

A driveway serving one townhouse, located in its front yard, may not exceed 50% of the lot width. On a 20 ft lot that is 10 ft — one car.
A driveway serving more than one townhouse may cover not more than 50% of the combined required street yards of the townhouses it serves.

These are the provisions that stop a townhouse row becoming a continuous paved frontage, and they interact directly with impervious cover and driveway limits.

What we watch on attached housing

Get the site-versus-lot distinction right before anything else. It is the single most common misreading of §25-2-772, and it decides whether a two-unit attached scheme fits on the land at all.

On townhouses, the 3,600 sq ft per unit is the binding number on most sites — more binding than the 20 ft lot width, which is generous. Work backwards from total site area to unit count rather than forwards from frontage.

And design the driveways early. A 50%-of-lot-width limit on a 20 ft lot is a real constraint on parking layout, and it is easier to solve on paper than after the units are placed.

Common questions

What is the minimum lot size for single-family attached in Austin?

3,000 sq ft per lot, within a site of at least 7,000 sq ft. The base district minimum lot size is superseded by §25-2-772.

How much land does a townhouse need in Austin?

At least 3,600 sq ft of site area for each townhouse, with a minimum lot width of 20 feet and at least two connected townhouses on the site.

What is the difference between single-family attached and a townhouse in Austin?

They are separate use types with different arithmetic. Single-family attached sets a 7,000 sq ft site and 3,000 sq ft lot minimum; townhouses set 3,600 sq ft of site area per unit and require a private yard.

How wide can a townhouse driveway be in Austin?

A driveway serving one townhouse in its front yard may not exceed 50% of the lot width. One serving several may cover not more than 50% of their combined required street yards.

Does single-family attached override my zoning district?

For that use, yes — §25-2-772(A) states the base zoning district regulations are superseded by the section.

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We do this research ourselves on every project we take on — zoning, floodplain, watershed, trees, whether it is a legal lot. Send us an address and we will run it and tell you what we find. It works the same whether you own a vacant lot, a house you are thinking of adding a unit to, or a house you are thinking of replacing. No charge and no strings, and if it is a bad lot we will say so.

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We 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.