Yes. Austin lets you add a second or third home on any SF-1, SF-2 or SF-3 lot of at least 5,750 sq ft, by right, under Land Development Code § 25-2-773 (HOME Phase 1, Ord. 20231207-001). Inside the central-Austin Subchapter F boundary each new unit is capped at the greater of 0.4 FAR or 2,300 sq ft, with the whole lot limited to 0.55 FAR or 3,200 sq ft for two units and 0.65 FAR or 4,350 sq ft for three; outside that boundary only the 40% building-cover and 45% impervious-cover limits apply. Height is the 35-ft base-district limit, setbacks are 15 ft front, 5 ft side and 10 ft rear (5 ft on an alley), and no off-street parking or owner-occupancy is required. Permitting is a standard Residential New Construction application: about $1,850-$2,150 in DSD plan-review and permit fees for an 800-1,200 sq ft unit and a 10-business-day first review.
Zoning & Size Requirements [1][2][3][4][5][6][7]
Yes — Austin allows ADUs. The size limit is a formula rather than one figure — see the size rule in the table below — under current Texas and Austin zoning rules.
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| Allowed Zones | SF-1, SF-2 and SF-3: two-unit and three-unit residential are permitted uses (§ 25-2-491 use table). Two-unit residential is also permitted in SF-5, SF-6, MF-1 to MF-6, CBD and DMU. The lot must be at least 5,750 sq ft (§ 25-2-773(B)(1)); small lots of 1,800-5,749 sq ft get one home only (§ 25-2-779). Deed restrictions, NCCDs and historic districts can still block a second unit. |
| Max Size (Detached) | No fixed cap outside the Subchapter F (McMansion) boundary: only 40% building cover and 45% impervious cover (§ 25-2-773(B)). Inside that central-Austin boundary a new unit may not exceed the greater of 0.4 FAR or 2,300 sq ft; the lot total is the greater of 0.55 FAR or 3,200 sq ft for two units and 0.65 FAR or 4,350 sq ft for three (§ 25-2-773(E), as amended by Ord. 20250424-073, eff. May 5, 2025). Garages and lofts count toward gross floor area; carports and porches do not. |
| Max Size (Attached) | An attached second unit is a duplex residential use under the same § 25-2-773 limits: greater of 0.4 FAR or 2,300 sq ft per new unit and 0.55 FAR or 3,200 sq ft for the lot inside the Subchapter F boundary; no unit-size cap outside it. The old 1,100 sq ft / 15%-of-lot ADU limit in former § 25-2-774 was repealed by HOME Phase 1 (Ord. 20231207-001, eff. Dec 18, 2023). |
| Max Size (JADU) | Austin has no junior-ADU category. A unit of 400 sq ft or less is a 'tiny home' (§ 25-1-21; IRC Appendix AQ) that counts as one of the two or three units and is permitted through the same residential application with a Request for Modification or Alternate Method of Compliance form. |
| Max Height | 35 ft: the SF-1, SF-2 and SF-3 base-district limit in the § 25-2-492(D) table. Subchapter F's 32-ft 'McMansion' height applies only to single-family residential use, not to duplex, two-unit or three-unit residential (Subchapter F § 1.2.2; DSD HOME Amendments page). |
| Max Units | 3 dwelling units per SF-1, SF-2 or SF-3 lot (§ 25-2-492 table; § 25-2-773), attached or detached in any combination, i.e. a house plus up to two ADUs, or a triplex. Zoning sets no minimum distance between units; IRC R302 fire separation still applies. |
Setback Requirements [1][2][3][4][5][6][7]
Austin requires a rear setback of about 10 ft for a detached ADU, and no additional parking is required. Owner-occupancy is not required — you can rent it out without living on the property.
| Rear Setback | 10 ft (SF-1/SF-2/SF-3 base district, § 25-2-492), reduced to 5 ft when the lot is adjacent to an alley or to a lot with a use permitted in a multifamily or less restrictive district (§ 25-2-773(B)(3)). |
| Side Setback | 5 ft interior side yard (§ 25-2-492). On a corner lot the street side yard is 10 ft from the property line on a Level 2, 3 or 4 street, or the greater of 5 ft from the line or 10 ft from the curb on a Level 1 street (§ 25-2-773(B)(4)). |
| Front Setback | 15 ft for duplex, two-unit and three-unit uses (§ 25-2-773(B)(2)); an open porch may sit 15 ft from the front lot line with its roof 13 ft. The 25-ft figure in the § 25-2-492 table applies only to single-family use. |
| Parking Required | None required. Austin repealed minimum off-street parking citywide in Ord. 20231102-028: § 25-6-471(A) reads 'off-street motor vehicle parking is not required'. If you build parking anyway, no more than four spaces may sit in the front yard and front-yard impervious cover is capped at 40% (§ 25-2-773(C)(2)). |
| Owner Occupancy | Not required. HOME Phase 1 removed the primary/secondary use distinction, so any of the units may be rented or sold as a condominium; the pre-2023 owner-occupancy and 'accessory apartment' language is gone from Chapter 25-2. |
| Min Lot Size | 5,750 sq ft for a second or third unit (§ 25-2-773(B)(1)). Lots of 1,800 to 5,749 sq ft in SF-3 or more restrictive districts may hold one 'small lot single-family' home only (§ 25-2-779(F), HOME Phase 2, Ord. 20240516-006). Lots may be re-subdivided down to 1,800 sq ft through the residential infill plat process (applications since June 16, 2025). |
Permit Process & Fees [8][9][10][11][12][13]
An ADU permit in Austin goes through a standard permit review. Typical timeline: DSD's published target is 10 business days for the first review of a New Construction application and 7 business days per update (Residential Plan Review page, targets revised July 1, 2026); garage conversions are 5 business days. Time to permit depends on how many review cycles you need. Permit fees: About $1,850-$2,150 in DSD fees for an 800-1,200 sq ft unit (FY2025-26 residential schedule, eff. Oct 1, 2025): $106.72 processing + $896.50-$1,220 plan review + roughly $840-$885 in building, electrical, mechanical, plumbing and energy permits; Austin Energy adds $220-$440.
| Approval Process | Residential New Construction or Addition building-permit application through DSD's AB+C portal: 1) confirm zoning and lot area on Property Profile, 2) get a new address from Address Management Services, 3) submit plans through the web form, 4) pay plan-review fees, 5) pay and activate the building and trade permits, 6) inspections, 7) Certificate of Occupancy. Fee-based Expedited Residential Plan Review (one sitting with all disciplines) and an AI 'Pre-Check' beta are optional. |
| Review Timeline | DSD's published target is 10 business days for the first review of a New Construction application and 7 business days per update (Residential Plan Review page, targets revised July 1, 2026); garage conversions are 5 business days. Time to permit depends on how many review cycles you need. |
| Permit Fees | About $1,850-$2,150 in DSD fees for an 800-1,200 sq ft unit (FY2025-26 residential schedule, eff. Oct 1, 2025): $106.72 processing + $896.50-$1,220 plan review + roughly $840-$885 in building, electrical, mechanical, plumbing and energy permits; Austin Energy adds $220-$440. |
| Impact Fees | No City impact fee for an ADU on an already-built lot: the Street Impact Fee applies only to redevelopment adding 10 or more PM-peak trips, and Transportation and Public Works states an ADU on a site with an existing structure owes none. Austin Water capital recovery (impact) fees are assessed per service unit only when a new or larger tap is added: $7,700 combined on lots platted after Oct 1, 2023, $7,200 for 2018-2023 plats, $800-$3,900 by zone for pre-2014 plats. |
| Plan Check | 10 business days for the first review (New Construction and Additions), 7 business days for each update submittal, 5 business days for garage conversions: DSD Residential Plan Review targets in force since July 1, 2026. Expedited review is a paid single-session alternative. |
| Pre-Approved Plans | None. The City has no pre-approved ADU plan library (Council Resolutions 20200409-080 and 20211209-064 only directed staff to study one, and DSD's ADU page lists none as of Sept 2026). What does exist: fee-based Expedited Residential Plan Review, the AI Pre-Check beta, and free 20-minute Residential Zoning appointments. |
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Construction Costs [14][15][16]
Building an ADU in Austin typically costs $150,000-$350,000 ($250-$450 per sq ft); a garage conversion runs $30,000-$100,000.
See what this means for your lot — ask Austin ADU builders for a quote →
| Average Build Cost | $150,000-$350,000 |
| Cost per Sq Ft | $250-$450 |
| Garage Conversion | $30,000-$100,000 |
| Prefab ADU (Installed) | $125,000-$300,000 |
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Rental Income Potential [17][18][19][20]
A 2-bedroom ADU in Austin rents for around $1,600-$2,300/mo, an estimated 5-9% gross rent yield (annual rent divided by build cost).
| Avg Rent (1 Bedroom) | $1,250-$1,850/mo |
| Avg Rent (2 Bedroom) | $1,600-$2,300/mo |
| Short-Term Rental | Yes, with a City STR operator's license (Code Ch. 4-23, in force Oct 1, 2025): up to two STRs on a lot of three or fewer units, $836.30 new / $385.30 renewal, two-year term, hotel occupancy tax applies. |
| Est. Annual ROI | 5-9% gross rent yield (annual rent divided by build cost) |
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Recent Law Changes
What's Changed Recently
- Ord. 20250424-073 (eff. May 5, 2025) amended § 25-2-773(E): inside the Subchapter F boundary, two new units on a lot that preserves an existing home may now total the greater of 0.65 FAR or 4,350 sq ft instead of 0.55 FAR or 3,200 sq ft.
- Ord. 20250227-039 and -040 (eff. Oct 1, 2025) moved short-term rentals out of the zoning code into new Chapter 4-23: an STR is an accessory use to every residential use with an operator's license, licenses run two years, and the old rule limiting an ADU built after Oct 1, 2015 to 30 STR nights a year was repealed with §§ 25-2-788 to 25-2-799 (DSD's ADU page still repeats the old rule; confirm with STR Licensing before listing).
- DSD reduced its published residential review targets from July 1, 2026: 10 business days for a new-construction first review, 7 for updates, 5 for garage conversions.
- Site Plan Lite Phase 2 and Infill Plat (adopted Mar 6, 2025; applications since June 16, 2025): re-subdivisions of up to one acre get streamlined drainage review, and lots created before June 16, 2025 need no drainage review for up to four units.
- Texas 89th Legislature (2025): SB 673, the statewide ADU pre-emption bill, died on the House calendar (last action May 26, 2025); SB 15, SB 840 and HB 24 contain no ADU provisions, so Austin's HOME rules stand on their own. The 90th Legislature convenes Jan 12, 2027.
- The FY2026-27 DSD fee schedule takes effect Oct 1, 2026; as of Sept 20, 2026 the posted residential schedule is still the FY2025-26 table (updated Sept 4, 2026).
Tips for Building an ADU in Austin
- Check the Subchapter F ('McMansion') boundary first: inside it (roughly the central city between US-183, Ben White Blvd, Loop 360 and Loop 1) FAR limits control unit size; outside it only 40% building cover and 45% impervious cover apply.
- 5,750 sq ft is a hard floor for a second unit under § 25-2-773. A 5,000 sq ft lot cannot add one, and Small Lot Amnesty cannot be combined with two-unit or three-unit use.
- Preserving at least 50% of an existing home built before 1961 (or 20+ years old) lets you exclude its preserved floor area from the FAR count (§ 25-2-773(F)); that is the route to two full-size new units on a central lot.
- Every new unit needs its own address from Address Management Services before you file, and the DSD ADU page lists a habitable space, a full bathroom and a kitchen sink or dishwasher as the three things that make a structure a dwelling unit.
- Garage conversions: a legally built garage converted without all three dwelling-unit elements (habitable space, full bathroom, and a sink or dishwasher outside the bathroom) is a Small Project ($132.86 plan review, 5-business-day target); add all three and it becomes a second dwelling unit that needs the full New Construction application, its own address and a Certificate of Occupancy.
- Deed restrictions and restrictive covenants override HOME: the City cannot waive them, so check your subdivision plat and any HOA rules before paying for design.
- Free 20-minute Residential Zoning Questions appointments (virtual or in person, Mon-Thu) will confirm zoning, lot area and setbacks before you hire a designer; extended fee-based consultations cost $443.87 for the first hour.
- Cost basis: AustinADU 2026 guide (Jan 15, 2026) $250-$400 per sq ft and $125K-$200K for 500 sq ft; Austin Tiny Homes (Feb 25, 2026) $200K-$350K typical, stick-built $240-$500+ per sq ft, turnkey prefab $125K-$300K; garage-conversion range from UHS Remodeling's Texas guide (Apr 24, 2026) $25K-$75K, up to $100K with a kitchen. Rents: HUD FY2027 SAFMR for central ZIPs 1BR $1,410-$2,050, 2BR $1,670-$2,440; Zumper Sept 20, 2026 medians $1,265 and $1,600.
ADU Builders in Austin
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Sources & References
All data on this page is sourced from official government records and verified market data. View our full methodology.
- Austin Land Development Code § 25-2-773 Duplex, Two-Unit, and Three-Unit Residential Uses (Municode, version Aug 26, 2026) Municipal Code — Accessed 2026-09-20
- Austin LDC § 25-2-491 Permitted Uses table and § 25-2-492 Site Development Regulations (Municode) Municipal Code — Accessed 2026-09-20
- Austin LDC Chapter 25-2 Subchapter F Residential Design and Compatibility Standards §§ 1.2, 2.1, 2.2 (Municode) Municipal Code — Accessed 2026-09-20
- Austin LDC § 25-6-471 Off-Street Parking (Municode) Municipal Code — Accessed 2026-09-20
- Ordinance No. 20250424-073 amending § 25-2-773 (FAR when preserving an existing unit), eff. May 5, 2025 ordinance — Accessed 2026-09-20
- Additional Dwelling Units | Austin Development Services Planning Department — Accessed 2026-09-20
- HOME Amendments | Austin Development Services Planning Department — Accessed 2026-09-20
- DSD Residential Building Plan Review & Inspection Permit Fees, FY2025-26 (effective Oct 1, 2025; updated Sept 4, 2026) fee_schedule — Accessed 2026-09-20
- Residential Plan Review | Austin Development Services (review times from July 1, 2026) Planning Department — Accessed 2026-09-20
- Expedited Building Plan Review | Austin Development Services Planning Department — Accessed 2026-09-20
- Street Impact Fee Program | Austin Transportation and Public Works (ADU FAQ) Government Data — Accessed 2026-09-20
- Rates and Fees, Impact Fee Schedules | Austin Water fee_schedule — Accessed 2026-09-20
- Council Resolution No. 20211209-064 (pre-approved ADU plans study direction) city_council — Accessed 2026-09-20
- AustinADU: How Much Does it Cost to Build an ADU in Austin? (2026 Guide, Jan 15, 2026) industry — Accessed 2026-09-20
- Austin Tiny Homes: ADU Cost in Austin 2026 (Feb 25, 2026) industry — Accessed 2026-09-20
- UHS Remodeling: Cost To Convert Garage Into Living Space In DFW Texas 2026 (Apr 24, 2026; figures as read by the Dallas agent 2026-09-20) industry — Accessed 2026-09-20
- HUD FY2027 Small Area Fair Market Rents, Austin-Round Rock-San Marcos, TX MSA ZIP codes Government Data — Accessed 2026-09-20
- Zumper Austin, TX rent research (updated Sept 20, 2026) Market Data — Accessed 2026-09-20
- Short-Term Rentals | Austin Development Services (license fees, Oct 2025 changes) Planning Department — Accessed 2026-09-20
- Austin City Code Chapter 4-23 Short-Term Rentals (Ord. 20250227-040, 20250911-012; Municode) Municipal Code — Accessed 2026-09-20
- Texas Legislature Online, SB 673 (89R) bill history state_legislature — Accessed 2026-09-20
- Texas Local Government Code Chapter 211, Municipal Zoning Authority state_statute — Accessed 2026-09-20
Frequently Asked Questions
Can I build an ADU in Austin?
Yes. ADUs are allowed in SF-1, SF-2 and SF-3: two-unit and three-unit residential are permitted uses (§ 25-2-491 use table). Two-unit residential is also permitted in SF-5, SF-6, MF-1 to MF-6, CBD and DMU. The lot must be at least 5,750 sq ft (§ 25-2-773(B)(1)); small lots of 1,800-5,749 sq ft get one home only (§ 25-2-779). Deed restrictions, NCCDs and historic districts can still block a second unit. in Austin. The maximum size for a detached ADU is No fixed cap outside the Subchapter F (McMansion) boundary: only 40% building cover and 45% impervious cover (§ 25-2-773(B)). Inside that central-Austin boundary a new unit may not exceed the greater of 0.4 FAR or 2,300 sq ft; the lot total is the greater of 0.55 FAR or 3,200 sq ft for two units and 0.65 FAR or 4,350 sq ft for three (§ 25-2-773(E), as amended by Ord. 20250424-073, eff. May 5, 2025). Garages and lofts count toward gross floor area; carports and porches do not.. Owner-occupancy is not required, so you can rent out the ADU.
How much does an ADU cost in Austin?
ADU construction in Austin typically costs $150,000-$350,000. Garage conversions run $30,000-$100,000, and prefab ADUs cost $125,000-$300,000.
How much can I rent an ADU for in Austin?
Average ADU rents in Austin are $1,250-$1,850/mo for a 1-bedroom and $1,600-$2,300/mo for a 2-bedroom unit.
Do I need parking for an ADU in Austin?
None required. Austin repealed minimum off-street parking citywide in Ord. 20231102-028: § 25-6-471(A) reads 'off-street motor vehicle parking is not required'. If you build parking anyway, no more than four spaces may sit in the front yard and front-yard impervious cover is capped at 40% (§ 25-2-773(C)(2)).. Check with Austin planning department for the latest Texas ADU parking rules, as many states have relaxed requirements in recent years.
How long does it take to get an ADU permit in Austin?
The permit review timeline in Austin is DSD's published target is 10 business days for the first review of a New Construction application and 7 business days per update (Residential Plan Review page, targets revised July 1, 2026); garage conversions are 5 business days. Time to permit depends on how many review cycles you need.. Permit fees: About $1,850-$2,150 in DSD fees for an 800-1,200 sq ft unit (FY2025-26 residential schedule, eff. Oct 1, 2025): $106.72 processing + $896.50-$1,220 plan review + roughly $840-$885 in building, electrical, mechanical, plumbing and energy permits; Austin Energy adds $220-$440.
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