Building an ADU in Texas

Texas has no statewide ADU law

Texas does not have a state law that makes cities allow ADUs; the 2025 bill that would have done so did not pass. Your city's zoning code decides whether you can add a backyard cottage, garage apartment or second unit, and on what terms.

State law gives a city council the power to regulate "the height, number of stories, and size of buildings," how much of a lot may be covered, the size of yards, population density, and the use of buildings and land. Those general zoning powers are where local ADU rules come from.

Start with your city's planning or development services department. For example, Austin allows additional dwelling units on certain single-family-zoned lots; see our Austin ADU guide. [1][2][6]

The 2025 ADU bill that failed: SB 673

SB 673, by Sen. Bryan Hughes, was titled "relating to municipal and county regulation of accessory dwelling units." It passed the Senate and was placed on the House calendar on May 26, 2025, but the House never passed it. It is not law.

The House committee version would have, among other things:

• barred owner-occupancy requirements;
• barred parking requirements on lots under 7,000 sq ft or within 1,320 feet of a public transit line;
• barred side and rear setbacks over five feet;
• barred size caps below 50% of the main home or 800 sq ft;
• required cities and counties to approve or deny ADU permits within 60 days.

Several House ADU bills (HB 878, HB 1779 and HB 2480) were referred to committee in March 2025 and went no further. None of these limits apply to your city unless a future law enacts them. [1][7][8][9][10]

Smaller lots in new subdivisions: SB 15

SB 15 took effect September 1, 2025. It applies only in a city with more than 150,000 people that is wholly or partly in a county with more than 300,000 people. Within those cities, it covers tracts of five acres or more, zoned for single-family homes, that will be platted and have no recorded plat yet.

On those tracts, the city may not require a residential lot to be larger than 3,000 sq ft, wider than 30 feet or deeper than 75 feet.

For a "small lot" (4,000 sq ft or less), the city may not require, among other things:

• a setback of more than 15 feet in front, 10 feet in back or 5 feet on the sides;
• covered parking, or more than one parking space per unit;
• more than 30% open space or permeable surface;
• fewer than three full stories (each up to 10 feet floor to ceiling).

The city may still require a shared driveway, permit fees equal to those for a single-family lot, impact fees allowed under Chapter 395, and setbacks for environmental features, erosion or waterways. Areas near airports, military bases and some law enforcement training centers are excluded.

SB 15 does not apply to land that already has a recorded plat, and it says nothing about ADUs. [3][4]

HOAs and deed restrictions still apply

SB 15 says it does not stop property owners from enforcing rules or deed restrictions imposed by a homeowners' association or other private agreement. Even where a city allows ADUs or small lots, your HOA covenants may not.

Read your deed restrictions before you design anything. Some cities, such as Austin, remind applicants that checking deed restrictions is the owner's responsibility. [3][6]

Neighbor protests of zoning changes: HB 24

HB 24 also took effect September 1, 2025. For most rezonings, a written protest signed by the owners of 20% of the land covered by the change, or of 20% of the land within 200 feet of it, still forces a three-fourths vote of the council.

Now, if a proposed change allows more residential development (and adds no new commercial or industrial uses, apart from limited ground-floor space), a protest by neighbors needs owners of at least 60% of the land within 200 feet. Even then, a majority of all council members can approve it.

A change that allows more housing and applies the same way to every parcel in one or more zoning districts (for example, a district-wide rule allowing ADUs) is a "proposed comprehensive zoning change." HB 24's protest procedure does not apply to those changes. [5]

Occupancy limits near big universities: SB 1567

SB 1567, effective September 1, 2025, applies only to home-rule cities with fewer than 250,000 people that have, or are next to, a college campus with more than 20,000 students. In those cities, zoning may not limit how many people live in a home based on whether they are related, their age, occupation or relationship status.

The city can still limit occupancy to no fewer than one person per bedroom of at least 70 sq ft, plus one more for each extra 50 sq ft of that bedroom. It can also apply building code, fire code and health limits. [11]

What to check with your city

Because the rules are local, ask your city planning or development services office:

• Which zoning districts allow an ADU, second unit or duplex, and the minimum lot size.
• The maximum ADU size, height and setbacks.
• Whether the owner must live on the property.
• How many parking spaces you need.
• Whether you can rent the ADU short term.
• The building permit, plan review and utility connection fees, including any impact fees.

Our ADU permit process guide, garage conversion guide, ADU cost guide and tiny house guide cover the general steps. [2]

Texas laws to know

• Local Government Code, Section 211.003

  Gives city councils the power to regulate building size, lot coverage, yards, density and land use, which is where ADU rules come from. [2]

• SB 15 (2025), Local Government Code ch. 211, Subchapter D

  In large cities, bars minimum lot sizes above 3,000 sq ft in new single-family subdivisions of 5+ acres and caps setbacks and parking on lots of 4,000 sq ft or less. [3][4]

• HB 24 (2025), Local Government Code Section 211.0061

  Raises the neighbor-protest threshold to 60% for zoning changes that allow more housing, and lets a majority of all council members approve them. [5]

• SB 673 (2025), proposed ADU law (did not pass)

  Would have required cities and counties to allow ADUs with limits on parking, owner occupancy and setbacks, and a 60-day permit deadline; it died in the House. [1][7]

Questions people ask