Building an ADU or guest house in Fort Worth

What Fort Worth allows

Fort Worth's zoning ordinance (Appendix A of the City Code) uses a narrow definition. "Dwelling unit, accessory" means "non-rented or leased living facilities within a detached building located on the same lot, parcel or tract of the primary dwelling unit for use or occupancy by temporary guests or a member of the family of the main dwelling unit, which does not contain cooking equipment."

So in Fort Worth an accessory dwelling unit is closer to a guest house or family suite than to a rentable backyard cottage. The code's rules for accessory buildings on residential lots add that in one-family districts a habitable accessory building "may be used only as an accessory dwelling unit and may not be used as a separate independent residence."

The code also defines a "temporary guest" as a nonpaying guest who does not use the unit as an address and stays no more than 14 days in a 30-day period.

Texas has no statewide ADU law, so these city rules control. See our Texas ADU guide and what is an ADU. [1][2][4]

Rules for a habitable accessory building

A guest house or other habitable accessory building on a residential lot must:

• meet all City of Fort Worth building code requirements for habitable structures;
• be no taller than the main house;
• meet the same side and rear setbacks as the main house in that zoning district;
• keep the total area under all roofs on the lot within the district's maximum lot coverage.

An accessory building connected to the house only by a breezeway or covered walkway, with a roofline that isn't part of the house, still counts as a separate accessory structure.

Size caps in the code (120 to 400 sq ft depending on lot size, or 2% of a lot of an acre or more) apply to non-habitable buildings such as sheds and workshops, not to habitable ones. Confirm how your design will be classified with the zoning staff. [2]

A second home on one lot: the B district

If you want a second unit you can rent, with its own kitchen, the zoning district matters. The city's zoning summary describes the "B" Two-Family district as allowing one-family and two-family homes, detached and attached, with a minimum lot size of 5,000 sq ft for two attached homes and 7,500 sq ft for two detached homes on one lot.

The one-family districts (A-2.5A, A-43, A-21, A-10, A-7.5, A-5 and AR) are described as for one-family detached homes. Ask the zoning staff at 817-392-8028 before you plan a second home. [3][5]

Garage apartments and conversions

Living space over a detached garage, or a converted detached garage, in a one-family district counts as a habitable accessory building when it contains space for living, sleeping or eating. It must meet the building code for habitable space and can't be used as a separate independent residence. Under the city's definition it can't be rented and can't include cooking equipment.

For non-habitable garages, the code allows one garage and one carport per unit on lots under half an acre. See our garage conversion guide for general steps. [1][2]

Small lots under state SB 15

Texas's 2025 small-lot law, SB 15, limits minimum lot sizes in new subdivisions in large cities. Fort Worth adopted Ordinance No. 28525-05-2026 to comply. It adds "small lot housing" as a new household living use allowed in all one-family districts, with development standards in a new Section 6.509.

SB 15 covers only unplatted tracts of five acres or more zoned for single-family homes, in cities over 150,000 people in counties over 300,000. It does not apply to land that already has a recorded plat. See our Texas ADU guide for what SB 15 covers. [6][7][8]

Short-term rentals

Fort Worth defines a "short term home rental" as renting "dwellings or accessory dwelling units" for overnight lodging for one night up to 30 consecutive days. In the city's residential district use table, short-term home rental is listed with no residential district marked as permitting it. Confirm with the zoning staff before listing any unit. [1][7]

Permits

Building permits run through the city's online system. The Development Services Department's CFW Permit Assist tool now shares a login with Accela Citizen Access, and information you enter in Permit Assist fills into Accela when you apply. The city says to verify fees by logging into your Accela account before paying, and that it never asks for payment by wire transfer.

Development Services is in City Hall at 100 Fort Worth Trail. Zoning questions go to 817-392-8028 or ZoningLandUse@fortworthtexas.gov. See our ADU permit process guide and ADU cost guide. [5][9]

Permit steps in Fort Worth

1. Check your zoning district

   Find out whether your lot is in a one-family district or the B two-family district. Call zoning at 817-392-8028. [3][5]

2. Decide what you're building

   In a one-family district, a habitable accessory building can only be a non-rented guest or family unit without cooking equipment. A rentable second home needs zoning that allows two units, such as B. [1][2][3]

3. Design to the setbacks, height and coverage limits

   Match the main house's side and rear setbacks, stay no taller than the main house, and keep total roof area within the district's lot coverage. [2]

4. Apply through Permit Assist and Accela

   Start in CFW Permit Assist, then submit and pay in Accela Citizen Access. [9]

5. Build to the building code and pass inspections

   Habitable accessory buildings must meet all City of Fort Worth building code requirements for habitable structures. [2]

Who to call

• Development Services, Zoning & Land Use

  Zoning district, accessory building and land use questions

  817-392-8028

  [5]

• Board of Adjustment (residential)

  Variances and special exceptions for residential lots

  817-392-2733

  [5]

• Development Services Department

  Building permits, Permit Assist and Accela

  817-392-1234

  City Hall, 100 Fort Worth Trail, Fort Worth, TX 76102

  [9]

Questions people ask