How do ADUs work in the City of Austin?
Within Austin city limits, ADUs are permitted through the Development Services Department. Since February 5, 2024, the HOME amendments let SF-1, SF-2 and SF-3 lots hold up to three housing units, and the separate "accessory" category for guest houses and accessory apartments was removed.
What changed with HOME Phase 2?
Phase 2, adopted May 16, 2024, created a small-lot single-family use for lots of at least 1,800 sq ft. It permits one unit per lot, so it matters more for subdividing than for adding an ADU, but it shows where city policy is heading.
Which neighborhoods are harder?
Lots inside the McMansion boundary face floor-area rules that count garages and lofts. Lots near creeks may carry floodplain limits, and older central neighborhoods often have large protected trees. Some subdivisions, especially newer ones, have deed restrictions that bar a second dwelling regardless of zoning.
Do you work outside these five cities?
Send your address anyway. Properties in unincorporated Travis or Williamson County follow county and extraterritorial rules, not city zoning, and may rely on septic systems. We tell you up front whether we can take the project.