Where the line is in Austin
From the City's exempt list and Residential Plan Review page, read 23 October 2026:
| Project | Permit | Review target |
|---|---|---|
| One-story detached accessory structure, 200 sq ft or less | None | — |
| Deck up to 200 sq ft, no more than 30 inches above grade (other conditions apply) | None | — |
| Garage conversion, carport or porch enclosure | Building permit | 5 business days |
| Uncovered wooden deck beyond the exemption | Building permit | 5 business days |
| Addition of any size attached to the house | Building permit | 10 business days |
| Additional dwelling unit | Building permit | 10 business days |
Floodplain lots, protected trees, wildland-urban-interface areas and Subchapter F setback rules add reviews; the City lists each with its own fee.
How to apply
- Check the property's history in AB+C Public Search and file an Acknowledgment of Expired Permits if there are open ones.
- Submit the New Construction or Addition web form with plans per the Building Criteria Manual: floor plans with dimensions, ceiling heights, doors and windows, smoke and CO detectors and plumbing fixtures, existing and proposed.
- Pay the review invoice; review starts then.
- Answer the Master Comment Report through the Modify a Residential Permit Application form (7-business-day target per update).
- Activate the building and trade permits and schedule inspections in AB+C.
Who can be the contractor: "In Texas, anyone can be a General Contractor, including homeowners, and a state license is not required" (Contractor Registration); registration with the City comes first. The trade work needs licensed, registered trade contractors, or an owner on a homestead trade permit doing that work personally.
What it costs
Plan review for additions and remodels, from the City's residential fee schedule effective 1 October 2026:
| Addition size | Plan review fee | At the top of the bracket |
|---|---|---|
| Up to 100 sq ft (base) | $197.23 | $197.23 |
| 101–200 sq ft | $394.46 + $1.972 per sq ft over 100 | $591.66 |
| 201–300 sq ft | $591.69 + $1.972 per sq ft over 200 | $788.89 |
| 301–400 sq ft | $788.92 + $1.972 per sq ft over 300 | $986.12 |
| 401–500 sq ft | $986.15 + $0.62 per sq ft over 400 | $1,048.15 |
| 501 sq ft and above | $1,048.12 + $0.1634 per sq ft over 500 | 800 sq ft: $1,097.14 |
Add the $112.76 application fee, the trade permits, $83.85 for each reinspection, and $585.77 if the plans have to be resubmitted. The right-hand column is our arithmetic from the schedule. Building costs are in home addition cost.
Inspections
Austin's building checklists run Layout, Foundation, Framing, Insulation, Wallboard and Final, with electrical (Temporary, Slab, Rough, Ground, Final), plumbing (Sewer Yard Line, Rough, Top-Out, Final) and mechanical (Rough, Final) as the scope needs (Building Inspections). The contractor schedules them in AB+C; the City says most happen about 24 hours after booking.
What 3,209 Austin addition permits show
| Measure | Austin additions |
|---|---|
| Permits on homes, October 2023 to September 2026 | 3,209 |
| Names on them (firms or individuals) | 1,378 |
| Names that appear exactly once | 839 (60.9%) |
| Reached Final (permits a year or more old) | 87.0% |
| Usual days from issue to Final | 238 |
| Firms with 10 or more permits | 35 |
| Busiest / quietest month | July (118) / November (76) |
Additions are the least concentrated work in Austin's file: 1,378 names for 3,209 permits, and only 35 with 10 or more. For most builders you will find a handful of permits at best, so read each one's dates and status rather than a percentage. Austin addition permits carry no job value.
See every Austin addition builder by permits filed and finished →
Next steps
Look the builder up on the Austin addition list, check subcontractor licenses with the Austin contractor license lookup, and read ADU vs addition if you are deciding between the two. Rules in other cities: do I need a permit for a home addition. Austin's monthly counts: Austin permit statistics; past permits on your lot: Austin building permit search.
What this does not tell you
Days to Final start at issue, so review time is not included. Fees change every 1 October.
How we know this
Exemptions, review targets, steps and the registration rule are quoted from City of Austin Development Services pages read 23 October 2026; fees from the residential fee schedule effective 1 October 2026, and the bracket totals are our arithmetic. Counts are City of Austin issued construction permits classified as additions, October 2023 to September 2026; finished share uses permits a year or more old, and days to Final is the median from issue to completion.
Numbers come from City of Austin issued construction permits, data through October 10, 2026. Nobody paid to be on this page and nobody can.
Questions
- Do I need a permit for a small addition in Austin?
Yes. Austin's exempt list stops at a one-story detached accessory building of up to 200 square feet and a deck of up to 200 square feet no more than 30 inches above grade. Anything attached to the house that adds floor area goes through Residential Plan Review.
- How much is an addition permit in Austin?
Plan review is priced by size: $394.46 plus $1.972 a square foot over 100 for a 101 to 200 square foot addition, $788.92 plus $1.972 a square foot over 300 for 301 to 400, and $1,048.12 plus $0.1634 a square foot over 500 above 500 (schedule effective 1 October 2026). A $112.76 application fee and the trade permits come on top.
- How long does an addition permit take in Austin?
The City's review target for New Construction & Additions is 10 business days from 1 July 2026, with 7 business days for each update. After issue, the usual Austin addition permit in our file reached Final 238 days later.
- Can a homeowner pull an addition permit in Austin?
Yes. The City says 'anyone can be a General Contractor, including homeowners', after registering with Building and Trade Contractor Services. The electrical, plumbing and HVAC permits need licensed trades, or the homestead trade permit if you do that work yourself on your homestead.
- Does a garage conversion need a permit in Austin?
Yes. Garage conversions and carport or porch enclosures go through Residential Plan Review on a 5-business-day target and are billed at the small projects rate of $146.15.
Build your own list
Every firm with that kind of permit on record. Pick what you value. The list moves.
Related guides
- Do I need a permit for a home addition? Yes in all 18 cities we read; here is what it involves
- Building a casita in Albuquerque: the 750 sq ft limit, rear-yard rule, parking, free plans, and who builds them
- Arlington's 2,500-square-foot rule: when an addition or new house needs a Land Disturbing Activity and stormwater permit
- Boulder's demolition review for houses over 50 years old: what counts as demolition, the fees, and the 180-day stay
- Do I need a permit for a garage or shed in Cook County? The 15-foot limit, the wiring rule, and 6,035 permits
- Do I need an HVAC permit in Cook County? The furnace and AC replacement form, and 10,735 permits
For one city
- Work Exempt from Building Permits — City of Austin Development Services (accessed 2026-10-23)
- Residential Plan Review — City of Austin Development Services (accessed 2026-10-23)
- Contractor Registration — City of Austin Development Services (accessed 2026-10-23)
- Residential Building Plan Review & Inspection Permit Fees (effective 1 October 2026) — City of Austin (accessed 2026-10-23)
- Building Inspections — City of Austin Development Services (accessed 2026-10-23)