ADU Rulebook

City · Texas

ADU rules in Fort Worth

6 sources

These are the primary sources for accessory dwelling unit regulations in Fort Worth: the city's own zoning code, planning department pages, and permit guides. Start here before talking to anyone: the rules below are what your permit reviewer will apply.

Rules at a glance

Detached (backyard) ADU
Conditional

Habitable accessory buildings are permitted by right as accessory uses in all one- and two-family districts, but in one-family districts they 'may be used only as an accessory dwelling unit and may not be used as a separate independent residence'. The ADU definition further limits occupancy to temporary guests or family members of the main dwelling and bars cooking equipment, so this is a guest house or family quarters, not a rentable independent unit.

Zoning Ordinance (Appendix A) § 5.301(c)(3); § 4.603; § 9.101
Attached or internal ADU
Not allowed

The code defines an accessory dwelling unit as living facilities 'within a detached building'. An attached second unit with independent living facilities would make the building a two-family dwelling, which is permitted only in the 'B' two-family district and denser districts, not in one-family districts.

Zoning Ordinance § 9.101 (Dwelling Unit, Accessory; Dwelling, Two-Family); § 4.603
Maximum size
No ADU-specific square footage cap; habitable accessory buildings may not exceed the height of the primary dwelling and count toward district lot coverage (for example 50% maximum in A-5). The lot-size-based table in § 5.301(b) (120 to 400 sq ft, or 2% of lots of an acre or more) applies only to NON-habitable accessory buildings.

Third-party sites claim a '900 sq ft or 50% of primary dwelling' ADU cap; no such limit appears in the current code text (2026 S-20).

Zoning Ordinance § 5.301(b), (c); § 4.705(c)
Owner occupancy
Not required

No explicit owner-occupancy requirement appears in the sections read, but a stricter occupancy rule applies instead: ADU occupants must be temporary nonpaying guests (14-day limit in any 30 days) or family members of the main dwelling's occupants.

Zoning Ordinance § 9.101 (Dwelling Unit, Accessory; Temporary Guest)
Extra parking
No ADU-specific parking requirement in § 5.301. District standards require 2 spaces per dwelling unit behind the front building wall plus 1 per bedroom over three (for example A-5, § 4.705(d)(2)); because an accessory dwelling unit is not a separate dwelling unit under the code, no additional spaces are triggered in the text read.

Parking is set per district in Chapter 4 rather than per accessory structure.

Zoning Ordinance § 5.301; § 4.705(d)(2)
Approval process
Permitted use

'Accessory use or building' is permitted by right (P*) in all residential districts subject to the § 5.301 supplemental standards; habitable accessory buildings must meet the city building code, which means a standard building permit, no discretionary zoning approval.

Zoning Ordinance § 4.603; § 5.301(c)(1)
Rental restrictions
ADUs cannot be rented at all: the definition is 'non-rented or leased living facilities' for temporary guests or family members of the main dwelling. Short-term home rentals (1 to 30 nights) are not permitted in any residential zoning district (the STR row is blank across the residential district use table), and permitted STRs elsewhere require city registration (Ord. 26005-02-2023).

The STR definition in § 9.101 expressly covers accessory dwelling units.

Zoning Ordinance § 9.101 (Dwelling Unit, Accessory; Short Term Home Rental); § 4.603
The fine print: 5 caveats that can change the picture
  • Fort Worth's 'accessory dwelling unit' is far narrower than the term usually means: a detached guest or family quarters with no cooking equipment that cannot be rented or occupied as an independent residence. There is no by-right path to a rentable backyard ADU in one-family districts under the current code.
  • A true second rentable unit requires two-family 'B' or denser zoning; the B district expressly allows two detached dwelling units on one lot (§ 4.707(b)(2), subject to § 6.502 development standards).
  • The § 5.301(b) square-footage table (120 to 400 sq ft by lot size) applies only to non-habitable accessory buildings; habitable accessory buildings are instead limited by district lot coverage, setbacks, and the height of the primary dwelling.
  • Widely circulated third-party claims of a '900 sq ft or 50% of primary dwelling' ADU size cap do not appear anywhere in the current code (2026 S-20 supplement).
  • Secondary sources report city staff are drafting zoning ordinance amendments with a council vote expected in 2026; the ADU rules could change, recheck before relying.

Summarized from Fort Worth's ordinance text, read July 2026; every row links the code section it came from. Rules often vary by zone and lot, so treat this as orientation, not a permit determination, and confirm with the planning department before you commit to a design.

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ADU regulations

Short-term rental rules

Planning to rent your ADU on Airbnb or VRBO? Fort Worth regulates short-term rentals separately; check these before counting on nightly rental income.

Spotted something outdated?

Zoning codes change. If a link is dead or Fort Worth has updated its ordinance, report it and we'll verify against the official source.

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