ADU rules in Port Aransas

One ADU is expressly allowed per single-family residence, and it may be a directly adjacent stand-alone structure. ADUs are allowed in any zoning district where a single-family residence exists or is being newly permitted, but not on a lot that already contains two or more dwelling units. RVs, campers, mobile homes, and modified container vans cannot serve as the ADU.

The ADU may be located in the same building as the principal dwelling, and the §25-1 definition covers a secondary unit 'either in, added to, or detached from' an existing single-family residence, for use as a complete independent dwelling unit. Only one ADU is permitted per single-family residence.

The size rule is a window, not just a cap: the ordinance requires no less than 300 sq ft and less than 600 sq ft of air-conditioned space. §25-154(a) confirms the 300 sq ft floor as an express exception to the citywide 600 sq ft minimum dwelling size. On lots sized for multifamily development, a unit of 600 sq ft or more is treated as a second dwelling unit rather than an ADU.

Division 5 imposes no requirement that the owner live on the property to build an ADU or rent it long term. Owner occupancy matters only for the narrow short-term-rental grandfather clause: transient rental of an ADU requires the owner to permanently live on site with the property designated as their Nueces County homestead, and that pathway sunsets by August 5, 2026.

Each bedroom in the ADU triggers one additional space under §25-176(6). The citywide table in §25-161 separately requires 2 spaces for the single-family dwelling itself, and individually owned or assigned enclosed garages do not count toward required spaces; stacked parking is allowed for residential units.

An ADU is an allowed accessory use to a single-family home and is constructed 'only through the issuance of a building permit'; no conditional use permit, special permit, or public hearing is involved. It is allowed on any legally platted lot in any zoning district with an existing or newly permitted single-family residence, provided setbacks and density regulations are met.

The Chapter 12 STR regime defines an 'accessory short term rental' as a long-term-occupied primary home with a legal ADU used for STR, and layers on a permit before renting or advertising, the permit number in every ad, occupancy caps, a 24/7 local contact, inspections, and signage. As of this verification the ADU STR grandfather window closes within days (August 5, 2026), after which short-term rental of any ADU appears fully prohibited.