Doña Ana County, NM Building Setbacks & Zoning: Lot Coverage Limits (2026)

Lot coverage in unincorporated Doña Ana County is set per zoning district under § 350-502C(5), which states "lot coverage shall be per Tables 5.4 through 5.17." For the T2/R5/R5L Rural and Rural 5-Acre zones, the County's common large-lot residential districts (minimum 2 acres in T2, 5 acres in R5 and R5L), Table 5.4 sets a specific numeric cap: "8.1 Lot coverage: 12,500 square feet or 10% of the lot size, whichever is greater, excluding the residential access driveway." On a standard 5-acre R5 lot (217,800 square feet), the cap works out to roughly 21,780 square feet, since the ordinance takes whichever figure is larger.

The same table separately caps encroachments into the setback: a portal is capped at "16% of setback (maximum), but no more than 8 feet," and a balcony or bay window at "8% of setback (maximum), but no more than 4 feet." By contrast, the County's more urban use zones, D1 Low Density Residential (Table 5.8), D2 Medium Density Residential (Table 5.9), and D3 High Density Residential (Table 5.10), each list "Lot Coverage: not applicable," leaving overall building footprint unrestricted in those districts aside from the individual setback and accessory-building-size limits that still apply.