Building an ADU in Dallas

Can you build an ADU in Dallas?

Usually not by right. On June 27, 2018, the City Council approved two ways to allow ADUs to be built or rented. The city's ADU page says "action is required by the City (on one of the two options below) before an ADU can be built. ADUs are not allowed to be built by right in most cases."

The two routes are:

• a special exception from the Board of Adjustment for one property;
• an Accessory Dwelling Unit Overlay, a zoning overlay a neighborhood applies for together.

In the overlay ordinance, an ADU is "a rentable additional dwelling unit, subordinate to the main unit, located on a building site with a single family use." Texas has no statewide ADU law, so Dallas's development code decides. See our Texas ADU guide and what is an ADU. [1][5][6]

Route 1: a Board of Adjustment special exception

The Dallas Development Code gives the Board of Adjustment two kinds of special exception:

• Additional dwelling unit (not rented). The board may allow it "in any district" if the unit will not be used as rental accommodations or adversely affect neighboring properties. The board "shall require the applicant to deed restrict the subject property to prevent use of the additional dwelling unit as rental accommodations."
• Rentable accessory dwelling unit. The board may allow it "in any district" if it "will not adversely affect neighboring properties." The board must require you to deed restrict the property to require owner occupancy, and to register the rental each year with the city's single-family non-owner-occupied rental program.

For a rentable ADU, if you don't provide at least one more off-street parking space, the board decides whether that creates a traffic hazard and may require the space.

The city's ADU page says you have the burden of proof, the board "does not consider how the appeal may benefit the applicant," and "no case sets a precedent." It lists a filing fee of $600.00 for an ADU exception. That page dates from the city's 2020 ADU review, so confirm the current fee with Board of Adjustment staff. [1][2][3]

How to apply to the Board of Adjustment

The Board of Adjustment has three five-member panels that hear requests for variances and special exceptions. To start, you send a complete set of prescreen documents to staff by email at BOAprescreen@dallas.gov. Staff decide whether your project needs board action. Only when staff tell you to do so do you file the formal application through the DallasNow portal.

The board posts a prescreen goal date and a noon intake deadline for each hearing period. See the Board of Adjustment page for the current schedule, or call 214-948-4480. [7]

Route 2: a neighborhood ADU overlay

An ADU overlay lets everyone in an area build ADUs under one set of rules. The process, set in Section 51A-4.510:

• A neighborhood committee of owners of at least 10 properties asks the city for a petition form.
• The area must allow single-family uses and must not expressly prohibit ADUs. It must contain at least 50 single-family homes in a compact area, or be a whole original subdivision with fewer.
• City staff hold a neighborhood meeting. The petition needs signatures from more than 50% of owners. The fee is waived if 75% or more of the lots sign.
• The City Plan Commission and then the City Council hold public hearings.

Once an overlay is in place, owners there can apply to Building Inspection for ADU permits. [1][6][8]

Size, height and setbacks

Inside an ADU overlay, Section 51A-4.510 (adopted in 2018) sets:

• detached ADU: at least 200 sq ft, and at most the greater of 700 sq ft or 25% of the main structure;
• attached ADU: at most the greater of 700 sq ft or 25% of the main use;
• one story maximum; height no more than the main home, except an ADU over a detached garage may reach the zoning's maximum height;
• side yard of 3 feet if the structure is under 15 feet tall and in the rear 30% of the lot; rear yard of 3 feet if under 15 feet tall; taller structures follow the base zoning setbacks;
• no ADU in front of the main structure without a special exception.

An overlay ADU "may not be sold separately from the main building." If you rent either unit, the owner must live in the main house or the ADU, and the rental must be registered with the city.

Outside an overlay, Dallas's general accessory structure rules apply (except in the agricultural district): an accessory structure can't be taller than the main building, and each one may not exceed 25% of the main building's floor area, not counting parking. All accessory structures together are capped at 50%. [2][3][6][8]

Parking

Dallas adopted citywide parking reform on May 14, 2025. Single-family and duplex homes now need a minimum of 1 space per dwelling unit in R, D and TH zoning districts, and no minimum elsewhere. There are no minimums for any use within half a mile of light rail and streetcar stations.

The ADU rules, adopted in 2018 and still in the code, have their own parking terms. For a rentable ADU by special exception, the board may require one extra space. In an overlay, one space is required unless the ADU is within 1,200 feet of a DART bus or transit stop. Ask city staff how the 2025 ratios apply to your ADU. [2][6][8][9]

Building permits

After you have a special exception or are inside an overlay, you apply for a building permit through DallasNow, the city's online permitting portal. The city's Residential Permits page has the Residential New Construction Checklist, the Residential Addition Checklist, and the water and wastewater service installation application. For help call 214-948-4480.

Under the development code, each dwelling unit must have separate utility services. A lot for a single-family use in a single-family, duplex or townhouse district may have only one electric service and meter unless the board grants a special exception; an overlay lot may have up to two.

On April 23, 2025, the City Council approved changing Dallas's residential building code from a one- and two-family code to a One- to Eight-Family Dwelling Code, so buildings with up to eight units can be built using residential-based codes instead of the International Building Code. See our ADU permit process guide and ADU cost guide. [2][6][10][11]

Zoning reform in progress

Dallas is rewriting its Development Code. The city's zoning reform project says one goal is to "encourage a wider range of housing options." As of September 2026 the project was moving toward release of the first public draft of the updated code. Follow the Dallas Zoning Reform site for updates. [4]

Permit steps in Dallas

1. Check your lot

   Find out whether your property is in an ADU overlay. Outside an overlay, an ADU is not allowed by right in most of Dallas. [1]

2. Choose a route: special exception or overlay

   Apply to the Board of Adjustment for your lot, or work with neighbors on an ADU overlay petition (owners of at least 10 properties form the committee). [1][6][8]

3. Submit Board of Adjustment prescreen documents

   Email the prescreen package to BOAprescreen@dallas.gov. File the formal application in DallasNow only when staff tell you to. The city's ADU page lists a $600 filing fee. [1][7]

4. Attend the briefing and hearing

   The board administrator schedules the case and notifies you. You carry the burden of proof. A rentable ADU approval comes with an owner-occupancy deed restriction and yearly rental registration. [1][2]

5. Apply for the building permit in DallasNow

   Use the Residential New Construction Checklist and submit plans through DallasNow. [10]

6. Build, pass inspections and register the rental

   If you rent the ADU, register it each year with the city's single-family rental program as the approval requires. [2][6][8]

Who to call

• Board of Adjustment (Planning & Development)

  ADU special exceptions, prescreen review and hearing schedule

  214-948-4480

  [7]

• Planning & Development, Residential Permits

  Building permits, checklists and DallasNow help

  214-948-4480

  [10]

• Dallas Zoning Reform team (Planning Department)

  Development Code rewrite

  (214) 670-4209

  [4]

Questions people ask