Casita Regulations in Tucson

As of November 21, 2024, the Unified Development Code (UDC) was amended to comply with state requirements for casitas/ADUs.

The UDC permits casitas on parcels in zones that permit residential uses.

• Two casitas can be built on parcels with one existing family dwelling
• A third casita is allowed on parcels over one acre, but one casita must be restricted to affordable housing (defined as being affordable for households making 80% of the area median income or less)
• One casita can be built on a parcel with a duplex
• When building on parcels with an existing and occupied family dwelling, commercial standards are not applied
• Casitas can be 75% of the primary structure size, up to 1,000 sq ft
• Casitas can be up to 650 sq ft, regardless of the primary structure’s size
• Casita heights match the single-family home limits in the same zone (generally 25 feet)
• Rear and side setbacks are 5 feet from the property line
• A cool roof is required for newly built structures
• There are no parking requirements for casitas Casitas must have their own address issued by Pima County
• Casitas are not required to have separate utility metering as the primary residence
• Historic review is still required when building in Historic Preservation Zones and Neighborhood Preservation Zones

Dimensional Standards and Measurements are available in UDC Article 6.