ADU laws in Texas

In plain words

Texas has no statewide law about accessory dwelling units. An accessory dwelling unit, or ADU, is a second, smaller home on the same lot as a house. Examples are a backyard cottage, a garage apartment, or a unit inside the house. In Texas, each city decides whether ADUs are allowed and under what rules. Cities do this through zoning. Zoning is the local rulebook that says what can be built where. Some cities, like Austin and San Antonio, allow ADUs in most neighborhoods. Others, like Dallas, usually require special approval first. Houston has no traditional zoning, but its development rules still cap the size of a second unit. Outside city limits, counties have little zoning power. There, deed restrictions, septic rules, and flood rules usually matter most. A deed restriction is a private rule written into your property records. Homeowners association (HOA) rules can also ban ADUs, even where the city allows them. Lawmakers tried to pass a statewide ADU law in 2023 and again in 2025. The 2025 bill, SB 673, passed the Senate but never got a House vote. So no state rule protects your right to build one. The Legislature next meets in January 2027. If you want an ADU, start with your city's planning office and your deed and HOA papers. You may be able to build one if local rules and your property allow it.

The rules at a glance

What to do next

1. Find out whether your lot is inside city limits; if it is, look up your zoning district on the city's zoning map.
2. Read your city's ADU or accessory-structure rules, or call the planning or development services office, and ask about size, parking, owner-occupancy and setback limits.
3. Pull your deed restrictions and any HOA covenants from the county clerk or your HOA, since they can forbid an ADU even when the city allows it.
4. If you are outside a city or on septic, ask the county about on-site sewage, floodplain and subdivision rules before you design.
5. If you plan to rent the unit, check your city's short-term rental and occupancy rules first.

What your town still decides

Texas has no statute that requires or limits ADUs, so each city decides through its own zoning code whether ADUs are allowed, where, how big, and whether the owner must live on site. Houston is the big exception to normal zoning: it has no use-based zoning, but its Chapter 42 development rules cap secondary units, and private deed restrictions there can still forbid them. Outside city limits, Texas counties have little general zoning power, so the practical limits are usually deed restrictions, homeowners association (HOA) covenants, on-site septic rules, floodplain rules and county subdivision rules. Private deed restrictions and HOA rules can block an ADU even where a city allows one; the failed 2025 statewide bill (SB 673) would not have overridden them either. The 2025 housing laws the governor signed on June 20, 2025 and celebrated at a ceremonial signing on August 18, 2025 (SB 15 on lot sizes in new subdivisions in large cities, SB 840 on housing in commercial zones, and HB 24 on zoning protest petitions, all effective September 1, 2025) do not address ADUs. One related 2025 law, SB 1567 (effective September 1, 2025), stops home-rule cities under 250,000 people that host or border a university of 20,000+ students from limiting how many people may live in a home based on whether they are related; it can matter if you plan to rent an ADU to unrelated tenants in those college towns.

Examples of local rules

• Austin: Through its HOME rules, Austin allows up to three homes on most lots zoned SF-1, SF-2 or SF-3 (Phase 1, adopted December 7, 2023, in effect February 5, 2024) and dropped the old distinction between a main house and a secondary unit. Phase 2 (adopted May 16, 2024, in effect August 16, 2024) allows a single home on lots as small as 1,800 sq ft, but that smaller minimum is for one home only: the city's ADU page and its code for two- and three-unit lots (LDC 25-2-773) still require a lot of at least 5,750 sq ft to add a second or third unit. Other code limits still apply, ADUs built after October 1, 2015 face a 30-days-a-year short-term rental cap, and private deed restrictions can still block a project. Source
• Houston: Houston has no traditional zoning. City Council approved Chapter 42 changes on September 27, 2023 (effective November 27, 2023) that raised the maximum size of a secondary dwelling unit from 900 to 1,500 sq ft, with parking based on unit size. Active deed restrictions still override these city standards, so check your subdivision's restrictions first. Source
• San Antonio: One ADU is allowed per lot in the R-1 through R-6 and RM-4 through RM-6 districts. Every lot can have at least 800 sq ft; larger homes can have an ADU up to half their size, capped at 1,600 sq ft. The owner has to live on the property, in the house or the ADU, unless the lot is rezoned. Detached ADUs need at least 3 ft from side and rear lines, and one parking space is needed only above 800 sq ft. Source
• Dallas: Dallas says ADUs are not allowed by right in most cases. An owner can ask the Board of Adjustment for a special exception (filing fee $600), or a neighborhood can petition for an ADU overlay district, which needs signatures from more than half the owners plus hearings. Under the city's 2018 ordinance (No. 30930), a board-approved ADU must be deed-restricted against renting it out, unless the owner gets the separate rental exception, which requires a deed restriction that the owner live on the property and yearly rental registration. A 2020 effort to loosen the code was put on hold. Source

What we’re still confirming

• A statewide ADU bill like SB 673, which died in 2025, may be filed again when bill filing for the 2027 session opens in November 2026.
• Dallas's ADU deed-restriction rules date from a 2018 ordinance and may have changed since; confirm with the city.

Laws, bills and citations

This is general information, not legal advice. Your town, village, city or county decides what can be built on your property. If something here looks out of date, email the team.