Sahuarita, AZ Building Setbacks & Zoning: Lot Coverage Limits (2026)

The Sahuarita development standards tables in Chapter 18.12 establish maximum lot coverage percentages for each residential zone classification within the Town. These coverage ratios represent the maximum percentage of a lot that may be occupied by buildings and roofed structures, calculated as the ratio of total roofed area to total lot area. Suburban residential zones such as SR and MR, which comprise the majority of the newer residential development in Sahuarita including portions of Rancho Sahuarita, typically allow maximum building coverage of 40 to 50 percent of the lot area. This includes the primary dwelling, attached or detached garages, carports, covered patios, accessory dwelling units, storage sheds, workshops, and any other permanently roofed structures on the property. Rural zones including GR-1 and Conservation Ranch maintain lower coverage limits, generally in the range of 25 to 35 percent, reflecting the larger lot sizes of one acre or more and the intent to preserve open space character and desert landscape in these areas. Lot coverage calculations include all roofed structures regardless of whether they are enclosed, meaning covered patios and carports count toward the maximum even though they may not have walls on all sides. However, open at-grade improvements such as uncovered concrete patios, swimming pools, driveways, and walkways generally do not count toward the building coverage calculation, though they do contribute to impervious surface area for drainage and stormwater management purposes. The Town regulates impervious surfaces through the grading and drainage provisions in the landscaping standards of Chapter 18.73 and the riparian habitat protection requirements of Chapter 18.65, which may impose additional development limitations beyond the building coverage ratio. Projects within riparian buffer zones along the Santa Cruz River and its tributaries face the most restrictive development standards. Master-planned communities like Rancho Sahuarita often have specific plan standards that establish their own coverage ratios for each subdivision phase, typically consistent with or slightly more restrictive than the base zoning to maintain the community aesthetic and ensure adequate landscaping between homes. The Rancho Sahuarita architectural review committee evaluates proposed construction and additions for compliance with both the specific plan coverage standards and the community design guidelines. Exceeding the maximum lot coverage requires a lot development modification under Chapter 18.85, which the Board of Adjustment may grant only upon demonstration of a hardship unique to the specific lot, such as unusual shape, significant grade changes, or other physical conditions that prevent reasonable use of the property within standard coverage limits.