Austin site plan exemptions: when you do not need a site plan
The four-unit exemption, and the trap in it
The exemption most residential projects use is four or fewer residential units — but read the condition carefully. It is not four new units. The lot must contain four or fewer units including proposed and existing. Two existing units plus three new ones is five, and the exemption is gone.
The second condition is the floodplain: the improvement must be outside the 100-year flood plain, unless the director determines it will have an insignificant effect on the waterway. That second clause is a judgement call, not a right.
construction or alteration of four or fewer residential units, if: (a) the proposed construction is located on a legal lot or tract that contains four or fewer residential units, including proposed and existing units; and (b) a proposed improvement is not located in the 100 year flood plain, or the director determines that the proposed improvement will have an insignificant effect on the waterway;
| Exempt development | The condition attached |
|---|---|
| Four or fewer residential units | Counting existing units too, and out of the 100-year floodplain |
| Tree removal | Only trees not protected by Title 25 |
| Interior alteration | No increase in square footage, area or height |
| Fence | Must not obstruct the flow of water |
| Clearing for survey or testing | Up to 15 feet wide, and no tree over 8 inches diameter removed |
| Restoring a damaged building | Work must begin within 12 months of the damage |
| Relocation or demolition | Not more than 10,000 sq ft of site area, under a City demolition permit |
| ETJ development | Only if exempt from all water quality requirements of Title 25 |
| Commercial portable building | On existing impervious cover, no drainage impact, landscaping complies |
| Change of use | New use meets off-street accessible space requirements; not adult oriented businesses |
The Subsection (B) exemptions. Every one carries a condition, and the condition is where projects fail. Subsections (C) and (D) add further cases.
Demolition is exempt up to 10,000 square feet
Relocating or demolishing a structure or foundation is exempt where it covers not more than 10,000 square feet of site area and is done under a City demolition permit. For a house that is almost always satisfied — the threshold is aimed at commercial-scale removal.
Note this exempts you from the site plan. It does not exempt you from the demolition permit itself, which is a separate requirement.
An exemption is a determination, not a claim
§25-5-2(A) puts the decision with the director, who may require an applicant to submit information necessary to make it. So the practical sequence is not "we are exempt, therefore we proceed" — it is "we believe we are exempt, and the director agrees after seeing enough to decide."
That matters for programme: an exemption still involves the City, and the information they ask for is at their discretion.
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.