Tucson, AZ Accessory Structures: ADU Permits (2026)

On October 22, 2024 the Mayor and Council adopted UDC amendments to comply with Arizona House Bill 2720, which required cities over 75,000 residents to allow ADUs ministerially by January 1, 2025. The Tucson amendments became effective November 21, 2024. Key features: at least one ADU permitted per single-family lot; up to two ADUs per lot with an existing single-family home; a third ADU allowed on lots over one acre if deed-restricted as affordable to households at 80% AMI. Maximum size is 75% of the primary dwelling gross floor area, capped at 1,000 sq ft, with a 650 sq ft minimum allowance regardless of primary size. Vehicular parking is not required for ADUs. Minimum side and rear setbacks are 5 feet. Maximum height matches the single-family height in the underlying zone (typically 25 feet) under UDC 6.3 Dimensional Standards. Tucson requires cool roofs on new ADUs reflecting local climate policy. Applications file through PDSD's online permitting portal. Historic and neighborhood preservation zones receive additional design review but ADUs are not required to replicate the primary home's appearance.