Carrollton, TX Accessory Structures: ADU Rules (2026)

Article 35 of the Comprehensive Zoning Ordinance (updated April 2026) defines GARAGE APARTMENT as 'a dwelling unit attached to or erected above a private garage.' Because the definition itself calls it a dwelling unit, it runs headlong into Article 7, Section B, which governs the (SF) Single-Family Residential District classifications (SF-12/20 through SF-PH) and states plainly: 'Not more than one dwelling unit shall be allowed per lot of record.' A freestanding or above-garage apartment functioning as a second, independently occupiable home is therefore not a permitted use on a single-family lot, regardless of lot size or district.

What the ordinance does authorize as accessory living space is narrower. The Article 5 Use of Land and Structures table lists Use C012, 'Guest House or Servant's Quarters' (Ord. No. 1739, 10/01/91), marked 'A' for permitted accessory use in the single-family districts. Article 35 defines GUEST HOUSE as a structure that 'may contain dwelling accommodations for the temporary occupancy by guests,' and both the guest house and servants'-quarters definitions bar a separate utility meter and, absent Article 7 sign-off, a kitchen. In practice a homeowner can build living space above or beside a garage under the guest house or servant's-quarters use, but it cannot be marketed, separately metered, or occupied as an independent second dwelling. That line is enforced through the one-dwelling-per-lot cap in Article 7, Sec. B, and it shapes how the city reviews building permits for any structure with sleeping and kitchen facilities separate from the main house.