Texas ADU Rules by City: Where You Can Build in 2026

Accessory dwelling units occupy a strange position in Texas housing law. The state has some of the fastest-growing metros in the country, an acute affordability crisis in Austin and the Dallas–Fort Worth metroplex, and a Republican legislative majority that has spent the last three sessions debating housing preemption — yet Texas remains a local-control state when it comes to ADUs. Where California's Government Code §65852.2 forces every city to approve ADUs ministerially within 60 days, Texas leaves the decision entirely to city councils operating under the general zoning authority granted by Local Government Code Chapter 211. The result is a patchwork that can flip from permissive to prohibitive across a municipal line: Austin allows up to three units on a residential lot under its HOME Initiative, while a Dallas suburb 200 miles north may still require a special-use permit and a public hearing for a 600-square-foot garage apartment. If you are weighing an ADU in Texas in 2026, the first step is not "what can I build" — it is "which city am I in, and what does its zoning code actually say."

The Texas legal framework: no preemption, broad local authority

Texas zoning power flows from Local Government Code Chapter 211, which grants home-rule and general-law municipalities the authority to regulate the use of land, the height and bulk of buildings, and the density of population. Chapter 211 is the statutory cousin of California's planning and zoning law, but with one critical difference: Texas has never layered an ADU-specific preemption statute on top. A city's authority to ban or restrict accessory dwelling units derives directly from §211.003, which lets the city regulate "the location and use of buildings, other structures, and land for business, industrial, residential, or other purposes." Cities exercise that authority through their zoning ordinances and unified development codes, and the practical result is that ADU legality varies dramatically from one Texas city to the next.

The 88th Legislature in 2023 was the closest the state has come to changing that picture. Senate Bill 840, filed by Senator Bryan Hughes, would have required Texas municipalities of a certain size to permit at least one ADU on any lot zoned for a single-family dwelling, with statewide caps on parking requirements and owner-occupancy mandates. SB 840 cleared committee but died on the Senate floor without a final vote. Senate Bill 15, which did pass in 2023, addressed a narrower issue: it preempted residential lot-size minimums in cities of 150,000 or more population for subdivisions of five acres or more, effectively forcing the largest Texas cities to allow smaller lots. SB 15 is a real housing-supply statute, but it is not an ADU statute — it governs lot subdivision, not accessory units. The 89th Legislature in 2025 reopened the ADU question with several refiled bills, but none reached the governor's desk. As of 2026, ADU rules in Texas are city law, full stop.

HOA preemption: the missing piece

The other half of the Texas ADU puzzle is the homeowners' association. Texas Property Code Chapter 202 governs restrictive covenants and gives HOAs broad authority to enforce CC&Rs that limit accessory structures, second dwelling units, or rentals. Unlike California Civil Code §4751, which voids any HOA provision that "effectively prohibits or unreasonably restricts" an ADU, Texas has no statewide HOA preemption for accessory dwelling units. Property Code §202.018 prohibits HOAs from banning solar devices, §202.019 protects rainwater harvesting, and §202.023 protects religious displays, but no analogous provision protects ADUs. If your subdivision's CC&Rs prohibit second dwelling units or accessory structures over a certain size, your HOA can enforce that prohibition even if the underlying city code would otherwise allow the unit. Before you commission an architect, read your CC&Rs and the deed restrictions filed with the county clerk for your subdivision.

Austin: the most permissive city in Texas

Austin is the closest thing Texas has to a California-style ADU regime. The Austin Land Development Code §25-2-1463 governs accessory dwelling units in single-family zoning districts, and the city has rewritten the rule three times in five years. The most recent overhaul came through the HOME Initiative — Home Options for Middle-Income Empowerment — adopted in two phases by Austin City Council. HOME Phase 1, passed in December 2023, reduced the minimum lot size for residential development and increased the maximum number of units per residential lot from one to three. HOME Phase 2, adopted in May 2024, reduced the minimum lot size for single-family use from 5,750 square feet to 1,800 square feet, opening urban-lot-split opportunities citywide.

In practice, HOME means a typical Austin single-family lot in zoning categories SF-1, SF-2, or SF-3 can now host the primary dwelling plus two additional units — which can take the form of two ADUs, a duplex unit and an ADU, or other configurations. Each ADU is subject to objective design standards: maximum height of 30 feet for two-story units, side and rear setbacks of five feet, and a maximum impervious cover that varies by zoning district. Off-street parking is not required for ADUs within the urban core or near transit corridors, and the city eliminated the owner-occupancy requirement that had been the standard before HOME. Permit fees vary but a typical detached ADU in Austin will pay $3,000 to $7,000 in city fees before construction, with development impact fees layered on top for water and wastewater connections.

The political context matters. Austin's HOME Initiative survived a state court challenge in 2024 brought by neighborhood groups arguing that the city had bypassed required public notice procedures, and the underlying ordinance was upheld. Austin remains the Texas city most likely to allow an ADU by right, with the fewest discretionary review hurdles, and the largest pool of pre-approved plan sets available through the Development Services Department.

Houston: no zoning, but plenty of rules

Houston is the largest American city without traditional zoning, and the ADU conversation here is fundamentally different. Houston's land-use framework runs through Chapter 42 of the City Code — the development ordinance — and through deed restrictions enforced by neighborhood civic associations. There is no Houston "single-family zone" to preempt. Instead, Chapter 42 sets minimum lot sizes, minimum building lines, and parking requirements that apply across the city. Houston's minimum-lot-size rules have been progressively relaxed since the 1998 amendments inside Loop 610 and the 2013 amendments that extended smaller minimums citywide, and these reforms have done more for ADU-equivalent housing in Houston than any explicit ADU ordinance would.

The Houston equivalent of an ADU is typically called a "garage apartment" or "ancillary structure," and Chapter 42 generally allows them on lots of sufficient size, subject to setback and parking rules. The harder restriction is almost always the deed restriction. Most platted Houston subdivisions carry recorded deed restrictions enforced by the civic club or property owners' association, and many of those restrictions explicitly prohibit second dwellings or limit accessory structures to a maximum square footage. A garage apartment that is legal under Chapter 42 may still be unbuildable because the 1955 deed restrictions for your neighborhood ban anything beyond a "single residence." Houston also has historic district overlays — the Heights, Old Sixth Ward, Freeland — where the Houston Archaeological and Historical Commission adds another design-review layer. Before you build, pull the deed restrictions from the Harris County Clerk and check whether your subdivision is inside one of Houston's historic districts.

Dallas: special-use permits and the R-7.5 question

Dallas governs ADUs through the Dallas Development Code, codified in Volume II of the city code. The Development Code allows accessory dwelling units in some residential districts — particularly R-7.5(A) and R-10(A) zones — but typically by special-use permit rather than by right. Section 51A-4.217 of the Development Code addresses accessory structures generally, and the ADU-specific provisions sit within the single-family district sections. A typical Dallas ADU application goes to the City Plan Commission for a recommendation and then to City Council for the final SUP vote, a process that can take six to nine months and includes a public hearing where neighbors can testify against the proposal.

Dallas has been studying a more permissive ADU framework since 2022, when the City Plan Commission opened a comprehensive zoning amendment process to allow ADUs by right in certain single-family districts. The proposal has moved slowly through public engagement and has faced opposition from neighborhood associations in established areas like Lakewood, Preston Hollow, and the M Streets. As of 2026, the by-right path is not yet adopted citywide, and the SUP route remains the standard for ADUs outside a handful of mixed-use districts and the planned development areas that have embedded ADU allowances. Dallas impact fees for new residential construction are governed by the city's impact fee ordinance and currently run several thousand dollars for water and wastewater connections, payable at the time of building permit issuance.

San Antonio: the UDC and Section 35-372

San Antonio's Unified Development Code, Chapter 35 of the city code, is the most consolidated planning document among major Texas cities. Section 35-372 specifically governs accessory dwelling units, and the UDC permits ADUs in many single-family zoning districts, including R-3, R-4, R-5, and R-6, subject to a set of objective standards. The ADU must be subordinate in size to the primary dwelling, with a typical maximum of 800 square feet or 40% of the primary unit's floor area, whichever is smaller. Setbacks generally follow the underlying district, and side-yard and rear-yard minimums apply. The UDC requires one off-street parking space for the ADU in most districts, although the requirement is waived in certain transit-served areas and in the downtown overlay.

San Antonio's permitting process for ADUs is administrative — no special-use permit required in the districts where the UDC allows them — which makes it considerably faster than the Dallas SUP path. The Development Services Department reviews building plans and zoning compliance simultaneously, and a typical detached ADU permit cycles in 60 to 90 days assuming a complete application. The city has also been studying short-term rental restrictions on ADUs, and Chapter 16 of the city code requires short-term rental operators to obtain a permit regardless of whether the rental unit is the primary dwelling or an ADU.

Fort Worth: 2024 updates and the new ADU framework

Fort Worth overhauled its zoning ordinance in 2024 to create a clearer ADU pathway. The updated ordinance permits accessory dwelling units in most single-family districts, including A-5, A-7.5, and A-10, subject to size limits, setbacks, and design standards similar to other major Texas cities. Maximum ADU size in Fort Worth is generally 800 to 1,000 square feet depending on the underlying lot size, with a separate cap expressed as a percentage of the primary dwelling. The 2024 update eliminated the requirement that the property owner reside on-site, which had been a significant barrier to investor-built ADUs and to homeowners who wanted to rent both units while traveling.

Fort Worth's ADU permit process is administrative for most lots that meet the zoning requirements, with the Development Services Department issuing permits without a public hearing. The city's impact fees and water and wastewater connection charges apply, and ADUs are subject to the same building code and energy code requirements as primary dwellings. A typical Fort Worth ADU project will pay $4,000 to $9,000 in city fees before construction, with the variation driven primarily by the size of the unit and the water tap fee.

El Paso, Plano, Arlington, Corpus Christi, Lubbock: the suburban patchwork

The five other major Texas cities track a wider range of approaches. El Paso permits ADUs in some single-family districts under Title 20 of the city code, with size limits typically capped at 600 to 800 square feet and a parking requirement of one space per unit. El Paso's ADU activity is concentrated in the older neighborhoods near the central business district and the University of Texas at El Paso campus. Plano, by contrast, runs one of the more restrictive ADU regimes among large Texas suburbs — the Plano Zoning Ordinance generally treats accessory dwelling units as a separate dwelling unit that requires the underlying lot to meet duplex zoning standards, which are limited to specific zones rather than blanket single-family districts. The practical result is that most Plano single-family lots cannot host an ADU under current zoning, and a homeowner seeking one must usually pursue a zoning change or a planned development amendment.

Arlington's zoning ordinance permits accessory dwelling units in some single-family districts, subject to special exception approval by the Zoning Board of Adjustment. The size cap is 800 square feet or 40% of the primary dwelling, whichever is smaller, and the property owner must occupy either the primary dwelling or the ADU. Corpus Christi addresses ADUs through its Unified Development Code with attention to coastal-zone restrictions — Federal Emergency Management Agency flood-zone designations layer on top of the city's zoning rules, and lots in V zones, A zones, or coastal high-hazard areas face additional elevation and construction requirements that often make detached ADUs impractical or prohibitively expensive. Lubbock allows accessory structures broadly in single-family districts but treats true habitable second units more restrictively, generally requiring rezoning or a planned unit development amendment for new ADU construction.

Garage apartments: the original Texas ADU

Texans built the equivalent of accessory dwelling units long before the term entered the planning vocabulary. The "garage apartment" — a small dwelling above a detached garage, typically with a separate exterior staircase — is a fixture of older neighborhoods in Houston (the Heights, Montrose, Rice Military), Austin (Hyde Park, Clarksville, French Place), Dallas (Munger Place, Lakewood, Oak Cliff), and San Antonio (Monte Vista, King William). Many of these structures predate modern zoning codes and are grandfathered as legal nonconforming uses. The relevant question for a homeowner inheriting a property with an existing garage apartment is not whether to build it, but whether the existing structure is documented as a legal nonconforming use and whether substantial alterations would trigger compliance with current code. Most Texas cities maintain a process for verifying legal nonconforming status, often through the planning department or the building official. Pulling that paperwork before listing the property for sale or applying for a building permit is a low-cost step that can prevent expensive surprises.

Property tax treatment

Texas Tax Code Chapter 11 governs property assessment, and the addition of an ADU triggers a reassessment of the improved property at the next appraisal cycle. The county appraisal district — Harris CAD, Travis CAD, Dallas CAD, Bexar CAD, and the equivalent district in your county — adds the new improvement to the appraised value, and the additional value flows through to the tax bill. Texas has no equivalent of California's Proposition 13 acquisition-basis cap, so the entire improved property is reassessed at market value each year, subject to the homestead 10% cap on year-over-year appraised value growth for the homesteaded portion. The practical implication is that a $150,000 ADU addition will typically increase the property tax bill by several thousand dollars annually, depending on the combined city, county, and school district tax rate. Some Texas cities are considering ADU-specific tax abatements as a housing-supply incentive, but none has been adopted at the scale that would meaningfully change the economics.

Short-term rental overlap

Texas cities retain the authority to regulate short-term rentals separately from the ADU framework. The Texas Supreme Court's 2018 decision in City of Austin v. Zaatari clarified that cities can impose reasonable restrictions on short-term rental use of residential properties, including ADUs, though blanket bans have been challenged with mixed results. In practice, Austin's short-term rental ordinance distinguishes between Type 1 rentals (owner-occupied primary residence), Type 2 (non-owner-occupied), and Type 3 (multifamily with rental units), and the ADU on a primary residence parcel typically falls under Type 1 if the owner lives on-site or Type 2 if not. Type 2 license caps and density limits apply by neighborhood, and Austin has effectively closed Type 2 licensing in several residential neighborhoods. Houston requires short-term rental registration under Chapter 28-1 of the city code. Dallas, Fort Worth, San Antonio, and Plano all maintain separate short-term rental ordinances with registration requirements, occupancy limits, and noise standards that apply to ADUs used as short-term rentals.

Common pitfalls

Six issues recur in Texas ADU projects. First, deed restrictions — particularly in Houston and in master-planned communities throughout the metroplex — often prohibit second dwellings even when city code would allow them. Pull the restrictions from the county clerk before you commit. Second, septic capacity on unincorporated or peri-urban lots: counties enforce on-site sewage facility rules under Texas Administrative Code Chapter 285, and adding a second dwelling typically requires a septic upgrade and a new permit from the local county designated representative. Third, floodplain compliance: properties in FEMA Special Flood Hazard Areas — common in Houston, Corpus Christi, and the Brazos and Trinity River corridors — face elevation requirements that can add tens of thousands of dollars to ADU construction cost. Fourth, utility tap fees: water and wastewater connection fees for a separately metered ADU can run $5,000 to $15,000 depending on the city, and some utility districts will not permit a second meter on a single lot. Fifth, fire-rated wall assemblies between the ADU and the primary dwelling under the International Residential Code; cities adopt the IRC with local amendments, and the assembly requirements differ between attached ADUs, garage conversions, and detached ADUs. Sixth, HOA design review: even when the HOA's CC&Rs permit ADUs in principle, the architectural review committee typically retains discretion over exterior materials, roof pitch, color, and screening, and these reviews can add months to the project timeline.

How to check your city

Texas ADU law is local law. CityRuleLookup maintains an accessory structures page for every Texas city we cover, summarizing the current zoning rules, size limits, setback requirements, parking obligations, and permit contacts. Start there to understand the baseline, then confirm against the city's current zoning ordinance — Austin's Land Development Code, Houston's Chapter 42, Dallas's Development Code, San Antonio's UDC, Fort Worth's Zoning Ordinance, and the equivalent code for your municipality. If you are inside an HOA or a deed-restricted subdivision, pull the restrictions from the county clerk and read them before you spend a dollar on design. And if your city has not updated its ADU rules in the last five years, ask the planning department whether an update is on the council's work program — Texas cities have moved quickly when they decide to act, and a zoning change that opens ADUs by right can swing the economics of a project in a way no statewide preemption bill has yet managed to do.