Austin nonconforming uses: the 90-day rule that ends them
What makes a use nonconforming
§25-2-941 is one sentence: a land use that does not conform to current use regulations, but did conform to the regulations in effect when the use was established.
It is lawful. It arose legitimately and the rules changed underneath it.
And as with structures, §25-2-942 sets a fixed grandfather date: a use that conformed with the zoning regulations in effect on 1 March 1984 is a conforming use regardless of what Chapter 25-2 now says.
What does not count toward the 90 days
§25-2-945(B) excludes two kinds of gap from the calculation:
- a seasonal discontinuance of the use; and
- a temporary discontinuance for maintenance or repair.
So a business that genuinely closes for a season, or shuts while the building is worked on, is not running the clock. A business that simply stops trading is.
The distinction is worth documenting at the time rather than reconstructing later. If a use pauses, the reason for the pause is what decides whether the right survives — and the burden of showing it falls on whoever wants to resume.
If the building is damaged: a 90% cost test
§25-2-944 handles damage to a structure housing a nonconforming use, and its test is quite different from the one for noncomplying structures.
The structure may be repaired and the nonconforming use continued if the building official determines that the cost of repair does not exceed 90 percent of the value of the structure immediately before the damage.
No time limit, but a cost ceiling. Contrast §25-2-964 for a noncomplying structure: a 12-month window to begin, restricted to the same footprint, gross floor area and volume — with no cost test at all. A property can be subject to both articles at once, and they ask different questions.
Helpfully, §25-2-944(B) says no site plan approval is required for the repair — unless the building official determines both that a substantial change is proposed and that a site plan would otherwise be required to build something similar from new.
The four regulation groups
Not every nonconforming use is treated alike. §25-2-946 runs a table: find the column for the zoning district, find the row describing the use, and the intersection gives you Group A, B, C or D. The groups are then defined in §25-2-947, and they run from most to least restrictive.
Group A is the harshest, and it is the only one with an expiry. A Group A use must be discontinued not later than 10 years after it became nonconforming — but only where the use occurs:
- outside a structure; or
- in a structure valued at less than $10,000.
Meanwhile maintenance or improvement of the structure is limited to what the law requires for minimum health and safety — and the value of that work cannot be counted toward the structure's value, which stops you improving your way out of the $10,000 threshold. Otherwise a Group A use follows the Group B rules.
Group B allows the use to continue and the structure to be maintained, but:
- you may not increase the floor space or site area of a nonresidential use;
- you may not make a change that increases the required accessible spaces; and
- you may improve, enlarge or structurally alter the structure only if the cost is 20 percent or less of the structure's value before the improvement.
Two things are excluded from that valuation: work required by law for minimum health and safety, and improvements to a part of the structure used solely for a conforming use. So bringing a building up to code, or improving the conforming half of a mixed building, does not consume the 20 percent.
Groups C and D are more permissive — Group C begins by allowing the use to continue and the structure to be maintained without the Group B enlargement bar. Their detailed conditions are not set out here; check §25-2-947 for the group your use actually falls into.
Where this comes up for us
Almost always on acquisition rather than design. A property with an old commercial or multi-unit use in a residential district is worth what its use rights are worth, and those rights are more fragile than buyers assume.
The 90-day rule is the one we raise first. A vacant tenancy over a slow winter can end a use permanently, and §25-2-945(C) offers no route back. If a purchase is going to involve a gap in occupation, that gap needs managing deliberately — and the seasonal and maintenance exclusions are narrower than people hope.
The Group B 20 percent cap is the one that constrains plans. On an older building of modest value, twenty percent does not buy much, and the exclusions for health-and-safety work and for conforming portions are the levers worth understanding before pricing a scheme.
And we keep the two articles apart. A building can be a noncomplying structure housing a conforming use, a complying structure housing a nonconforming use, or both at once — and the answers come from different places.
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.