Monroe County, FL Building Setbacks & Zoning: Lot Coverage Limits (2026)

Monroe County caps how much of a Keys lot can be covered by buildings and pavement through a minimum open space ratio, or OSR, defined in Land Development Code Section 101-1 as the percentage of the total gross area of a parcel that must remain open space. Section 130-157 sets that ratio by land use district for permanent residential development in the unincorporated Florida Keys. 50 open space ratio, meaning no more than half the parcel can be occupied by structures, driveways and other impervious coverage.

20 floor. Other districts run far stricter: Native Area and Offshore Island parcels must stay 95 percent open, and Conservation land must stay 90 percent open, reflecting the county's Area of Critical State Concern designation and its limits on clearing native habitat. The county's Planning and Environmental Resources Department checks compliance at building permit review, and Section 130-156 requires that density and intensity standards apply cumulatively, so a parcel cannot exceed its district's combined development ceiling. Chapter 118 can impose an even stricter open space ratio where wetlands, hammock or other environmentally sensitive habitat is present, and the more restrictive of the two ratios controls under Section 101-2(1).

A homeowner who wants to add more paved area or a pool deck beyond the allowed coverage needs either a variance or a transfer of development rights; simply building over the ratio without one is not authorized by the code.