ADU rules in Denton

ADUs, attached or detached, are permitted by right in all seven residential districts (RR, R1, R2, R3, R4, R6, R7) and all three mixed-use districts (MN, MD, MR), and prohibited in SC, HC, GO, LI, HI, and PF. Detached units must sit to the side or rear of the main home; a side-yard ADU must be offset at least 3 ft behind the front building line, and accessory structures need a 3 ft setback from property lines and cannot encroach on easements. The lot's principal use must be a single-family detached dwelling, townhome, duplex, or triplex.

Attached ADUs are permitted by right in the same districts as detached ones. The unit must be fully attached to or within the principal dwelling, with attachment defined as either one-quarter of the ADU's total wall area connected to the principal dwelling or its floor and ceiling fully connected to it. Attached ADUs must meet the principal dwelling's setbacks, and every ADU needs its own exterior entrance plus cooking, sleeping, and sanitary facilities.

Since the January 13, 2026 Missing Middle amendment, an ADU may be as large as 800 sq ft even next to a small house, and larger homes support up to 75 percent of their own floor area. Square footage is measured per DDC 3.7.7, which counts gross area from the outside of exterior walls including garages and closets, making the cap tighter than a net-livable-area reading. The pre-amendment rule still shown on Municode (50 percent of the principal dwelling with a 1,000 sq ft cap on small lots) no longer applies.

Neither the current (July 2026) nor the prior codified version of the ADU standards contains any owner-occupancy requirement; the owner does not have to live in either unit. The full compiled DDC was searched for owner-occupied, which appears only in the Bed and Breakfast use definition and the glossary, never in the ADU standards. Denton regulates ownership instead: the ADU stays tied to the lot unless structured as a condominium, and it cannot be separately platted.

Table 7.9-I sets the ADU minimum at none, so the ADU itself adds no parking requirement. The catch is that a single-family detached home must keep its own 4 spaces per dwelling unit (not counting tandem garage spaces), so converting a garage to build the ADU means replacing the same number of spaces elsewhere on the lot. The pre-amendment codified rule on Municode (1 space per ADU bedroom) was eliminated by the January 2026 amendment.

The use table marks Accessory Dwelling Unit 'P' (permitted by right) in RR, R1, R2, R3, R4, R6, R7, MN, MD, and MR, subject to the 5.4.4A standards; the owner files a residential building permit with Development Services through the eTRAKiT portal. A second ADU on the same lot is the exception: it needs a discretionary Specific Use Permit and cannot push the lot past four dwelling units total.

Nothing in the ADU standards restricts renting the unit long term. Using the ADU as a short-term rental requires registering with Development Services first through the city's STR Permit System, with an inspection within the first six months. The ADU also cannot be sold separately from the main home except through a condominium association. The STR text was verified unchanged between the stale Municode supplement and the July 2026 city PDF, so the codified version is current.