ADU rules in Mesquite

A detached backyard ADU is possible only with a Conditional Use Permit approved by the City Council, and only in the AG agricultural and R single-family districts (R-1, R-1A, R-2, R-2A, R-3) on lots of at least 21,780 sq ft (half an acre). The use table leaves the D duplex, TNMR, and A multifamily columns blank, which §2-201.D defines as prohibited. The unit must sit in the rear yard behind the rear facade of the house, meet the primary structure's setbacks with at least a 10 ft rear setback, and one ADU per property is the limit.

Mesquite's definition of an accessory dwelling covers attached space too: any area beyond the principal dwelling with living, sleeping, and bathroom facilities that either contains a kitchen or has its own entrance not from inside the main house. Such a suite is the same Accessory dwelling unit use, so it needs the same City Council CUP and half-acre lot. The §2-603.N standards are written for backyard structures (rear-yard placement, 15 ft height cap), so an attached unit would likely need the council to modify conditions, which the ordinance allows. A plain garage conversion into extra living space within the primary dwelling (no kitchen, interior access) is a separate, simpler path under §2-202.E with building permits.

The size cap is small by regional standards, and the height rule effectively limits ADUs to one story. The council can modify these criteria case by case when it grants the Conditional Use Permit ('unless modified').

The property owner must live on the property; this is criterion 4 of the mandatory CUP conditions. Paired with the ban on renting or selling the ADU separately, Mesquite's rules are built for family members or personal use, not for creating an income unit.

An ADU property must have at least four off-street spaces arranged so any car can leave without moving another, double the single-family baseline. Most newer lots also carry a separate two-car enclosed garage requirement from the base code (post-1984 plats).

ADUs are marked 'C' in the residential use schedule: a Conditional Use Permit that only the City Council can grant after a Planning and Zoning Commission hearing and recommendation. Under §5-310 a CUP is processed as a zoning map amendment: public notice, two public hearings, and an adopted ordinance that stamps the property with a '-CUP' suffix on the zoning map. Approval is discretionary ('may be approved'), and the council can attach or modify conditions. Before October 2022 this was a Board of Adjustment special exception; Ord. No. 4990 switched it to the CUP process.

The zoning conditions flatly prohibit renting the accessory dwelling unit separately, so neither long-term tenants nor short-stay guests can lease it. Mesquite separately licenses all rentals: the STR license (Ord. No. 4954, adopted May 2, 2022) requires inspections and a local representative within 40 miles, and its eligible-structure list (detached and attached single-family, duplex, multifamily, townhouse, mixed use, manufactured home) does not include ADUs.