Waco, TX Accessory Structures: ADU Rules (2026)

Division 9 of Waco's zoning chapter, added by Ord. No. 2023-969 in November 2023, created the city's first accessory dwelling unit (ADU) standards. Sec. ' Sec. 3 sets the design rules. Only one ADU is allowed per lot, and it may have only one bedroom. A detached single-family primary home must already exist or be built alongside the ADU; ADUs aren't permitted with any other housing type. Detached ADUs need a ten-foot rear setback, five-foot side setback, the same front setback as the primary dwelling, and at least ten feet of separation from the primary structure, though adapted existing structures are exempt from these setbacks.

Attached ADUs simply follow the primary dwelling's zoning-district setbacks. Size is capped at 500 square feet or 30 percent of the primary dwelling's floor area, garages excluded from that calculation, whichever is greater, and height can't exceed the primary dwelling's height. Parking adds one space beyond the two required for the primary home, accessible from an alley where the lot abuts one. Lot coverage from buildings and paving can't exceed 75 percent, exterior materials must complement the primary dwelling, and the ADU must connect to the primary dwelling's city water and wastewater service rather than carry a separate utility account.