Austin urban home special use: 3,500 sq ft lots and the porch requirement
| Standard | Urban home | SF-3, for comparison |
|---|---|---|
| Minimum lot size | 3,500 sq ft | 5,750 sq ft |
| Minimum lot width | 35 ft | 50 ft |
| Maximum height | 35 ft | 35 ft |
| Front setback | 20 ft (15 ft for a full block face) | 25 ft |
| Street side setback | 10 ft | 15 ft |
| Interior side setback | 5 ft | 5 ft |
| Rear setback | 5 ft | 10 ft |
| Building coverage | 55% | 40% |
| Impervious cover | base district % — or 65% on a lot ≤4,000 sq ft | 45% |
From §25-2-1424(A)–(B). Note the impervious cover row: the default is whatever the base district allows, and 65% is available only on the smallest lots.
A smaller lot, a bigger footprint — and a shape you do not choose
The dimensional side is straightforwardly generous. Against SF-3, an urban home gets a lot 2,250 sq ft smaller, 15 feet narrower, a rear setback half the size, and building coverage 15 points higher.
What you give up is control of the form. The base code says almost nothing about what a house looks like; this article says a great deal:
- a covered front porch at entry level is required — minimum five feet deep and at least half the width of the building façade;
- the main entrance must face the front lot line;
- a garage must sit at least five feet behind the front façade, and if it is within 20 feet of that façade it may be no more than half the façade width;
- no parking in the front yard other than in the driveway.
Both the porch and the entrance requirements are lifted on a flag lot, which has no meaningful street frontage to address.
Three different front setbacks
§25-2-1424(B) gives a default and two variations, and which applies depends on what is happening around you rather than on your own lot:
- 20 feet — the default.
- 15 feet — if urban home special uses are proposed for the entire length of a block face. A coordinated redevelopment gets five feet back that a single infill lot does not.
- The adjoining average — where the use adjoins a legally developed lot whose front setback is less than 25 feet, the minimum equals the average of the front setbacks of adjoining lots.
That last limb works like the block average rule elsewhere in the code, and on an older street with houses close to the pavement it can pull the line well forward of 20 feet.
Driveways are capped at twelve feet
§25-2-1424(D) is unusually specific for Austin, where driveway widths are normally left to a standard drawing. In a front yard or street side yard the maximum width is:
- 12 feet; or
- where the driveway serves two or more dwelling units — 18 feet one-way, or 24 feet two-way.
Twelve feet is a single car width plus a margin. Combined with the ban on front-yard parking outside the driveway and the garage placement rules, the intent is plain: the front of an urban home is meant to read as a porch and a door, not as a parking court.
Open space, private and communal
Two separate requirements, and they stack:
- 200 sq ft of private open space per dwelling — §25-2-1424(H), for every urban home.
- 250 sq ft of community open space per lot — §25-2-1423, but only for a development of more than eight lots.
The eight-lot threshold is worth noting when laying out a scheme. A nine-lot development carries a community open space obligation of 2,250 sq ft that an eight-lot one does not — which is a real reason to think about where the line falls.
When this is the right tool
Where an NP ordinance permits it, an urban home is often a better answer than the small lot route for a deliberate small-lot development. The 3,500 sq ft minimum is larger than the 1,800 sq ft a small lot allows, but the 55% building coverage and the sub-4,000 sq ft impervious allowance make each lot work harder, and the form rules produce a street that reads coherently.
The form requirements are not a nuisance in practice — a five-foot covered porch across half the façade is a good porch, and most clients want one anyway. The one that constrains design is the garage: five feet behind the front façade, and half the façade width if it is close. On a 35-foot-wide lot that rules out the double garage people often assume.
The first question remains the ordinance. These standards are worth nothing unless your neighborhood's NP ordinance prescribes the use for your lot.
Common questions
Send us an address and we will tell you what we find
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.
Send us an addressWe 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.