Austin residential zoning districts compared: SF-1 through SF-6
| SF-1 | SF-2 | SF-3 | SF-5 | SF-6 | MF-1 | |
|---|---|---|---|---|---|---|
| Min lot size | 10,000 | 5,750 | 5,750 | 5,750 | 5,750 | 8,000 |
| Min lot width | 60 ft | 50 ft | 50 ft | 50 ft | 50 ft | 50 ft |
| Max units / lot | 3 | 3 | 3 | — | — | see §25-2-560 |
| Max height | 35 ft | 35 ft | 35 ft | 35 ft | 35 ft | 40 ft |
| Front setback | 25 ft | 25 ft | 25 ft | 25 ft | 25 ft | 25 ft |
| Street side | 15 ft | 15 ft | 15 ft | 15 ft | 15 ft | 15 ft |
| Interior side | 5 ft | 5 ft | 5 ft | 5 ft | 5 ft | 5 ft |
| Rear | 10 ft | 10 ft | 10 ft | 10 ft | 10 ft | 10 ft |
| Building coverage | 35% | 40% | 40% | 40% | 40% | 45% |
| Impervious cover | 40% | 45% | 45% | 55% | 55% | 55% |
| Floor-to-area ratio | none | none | none | none | none | none |
From the §25-2-492 site development regulations table. SF-4A and SF-4B are governed separately — see below. Lake Austin (LA) and Rural Residence (RR) allow one unit per lot and require 43,560 sq ft.
No residential district sets a floor-to-area ratio
Look at the last row. It is empty for every single-family district, and that is not an omission — base zoning simply does not set a FAR for residential districts. The FAR column in §25-2-492 only starts carrying values at the multifamily and commercial districts.
So if you are looking up "SF-3 FAR" you will not find it in the district. Floor area comes from somewhere else entirely, depending on what you are building:
- Subchapter F — 0.4 or 2,300 sq ft, for one dwelling inside the McMansion boundary;
- §25-2-773 — 0.55 or 3,200 for two units, 0.65 or 4,350 for three;
- §25-2-779 — 1,650 or 0.55 on a small lot.
Outside the Subchapter F boundary, building one house, there may be no floor area cap at all — only coverage, setbacks and height.
SF-2 and SF-3 are dimensionally identical
Every number in the table is the same for both. The difference is historical and sits in the designation language, not the standards.
SF-2 is "the designation for a moderate density single-family residential use on a lot that is a minimum of 5,750 square feet."
SF-3 is "the designation for a moderate density single-family residential use and a duplex use on a lot that is a minimum of 5,750 square feet."
SF-3 was the district that permitted duplexes. That distinction has largely dissolved: HOME Phase 1 made Duplex, Two-Unit and Three-Unit Residential permitted uses in SF-1, SF-2 and SF-3 alike, and set maximum dwelling units per lot to three in all three.
So the practical difference between an SF-2 lot and an SF-3 lot today is close to nothing. What still differs is the overlays that happen to sit on top.
Two things they genuinely share: a five-foot rear setback for single-storey accessory buildings, and the §25-2-556 route to 55% impervious cover on qualifying lots. SF-3 alone carries retirement housing standards. The SF-3 page covers all three, and the SF-2 page covers why the code's own designation text still has not caught up with HOME.
SF-1 is the one that is genuinely different
Four rows set it apart, and no others: a 10,000 sq ft minimum lot and 60-foot minimum width, plus lower building coverage at 35% and impervious cover at 40%. Its setbacks and height are the same as SF-2 and SF-3.
The designation explains why. SF-1 "may be applied to a use on land with sloping terrain or environmental limitations that preclude standard lot size, or to a use in an existing residential development on a lot that is 10,000 square feet or more."
It is not simply "SF-3 for bigger lots". It is frequently a response to terrain, and that context tends to come with other constraints — watershed limits and slope-based net site area reductions that bite well before the zoning numbers do.
Note that SF-1 still got three units under HOME, same as SF-2 and SF-3 — and that its 10,000 sq ft minimum is not the floor for subdivision, because §25-2-779 reaches SF-3 "or more restrictive". The SF-1 page works through both.
The MF districts work on a completely different principle
Everything above is single-family, where density is a maximum number of units per lot. The multifamily districts do not work that way at all. MF-1 through MF-5 set a minimum site area per dwelling unit that varies by bedroom count, so the number of units depends on the mix you build. MF-6 sets none.
That is also why the maximum dwelling units cells for the MF districts in the table above carry footnote markers instead of numbers — they point at the regulation sections rather than stating a figure. The multifamily page has the full schedule, the derived densities, and the §25-2-567 affordability route to MF-6 standards.
SF-4A and SF-4B are not in the table
Both carry footnotes instead of values. SF-4A points to §25-2-779 (Small Lot Single-Family Residential Use) and §25-4-232 (Small Lot Subdivisions); SF-4B points to §25-2-558 (Single-Family Residence Condominium Site District Regulations).
That is worth knowing before you go looking for an SF-4A row that does not exist. The small-lot regime replaced it wholesale, and HOME Phase 2 rewrote that regime again.
What the districts are supposed to do
§25-2-51 states the purposes, and they are worth reading because they explain the shape of the standards:
- reserve areas for residential occupancy and provide a broad range of densities and housing types;
- ensure adequate light, air, privacy and open space for each dwelling;
- encourage compatibility between residential and other land uses;
- facilitate planning for infrastructure to serve anticipated density, traffic and public service requirements; and
- promote energy conservation.
The second one is the origin of nearly everything in the table — setbacks, coverage limits, the setback planes. Once you read the standards as answers to "adequate light, air, privacy and open space", the numbers stop looking arbitrary.
What we actually check first
Not the district. The district tells you surprisingly little now that HOME has levelled SF-1, SF-2 and SF-3 on unit count, and the numbers across those three barely differ.
What matters more, in order: whether the lot is inside the Subchapter F boundary, what overlay sits on it, what watershed it is in, and how wide it is. Those four decide far more than the two letters and a number on the zoning map.
The exception is SF-1. When we see it, we look at the terrain — because the designation exists partly to describe land that could not be platted at standard size, and the reason it could not usually still applies.
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.