Sahuarita, AZ Accessory Structures: ADU Rules (2026)

Accessory dwelling units, often called guest houses or casitas in the Southwest, may be permitted in certain Sahuarita residential zoning districts. The zoning ordinance establishes conditions including minimum lot size, maximum ADU square footage (typically limited to a percentage of the primary dwelling or an absolute maximum around 800-1,000 square feet), and setback requirements from property lines. ADUs must maintain the architectural character of the primary dwelling and neighborhood. Building permits are required for new ADU construction, including foundation, framing, electrical, plumbing, and mechanical inspections. Kitchen facilities in the ADU may be restricted depending on the zoning classification, as a full kitchen can change the classification from accessory structure to a separate dwelling unit with different regulatory requirements. ADUs must comply with all building codes including fire safety, energy efficiency, and accessibility standards. Parking requirements may increase with an ADU, potentially requiring an additional off-street parking space. Rancho Sahuarita HOA may restrict or require architectural review for ADU construction, and lot sizes in the planned community may not meet minimum requirements for ADU addition. Short-term rental of ADUs is subject to the same ARS 9-500.39 regulations as any residential unit.