Monroe County, FL Environmental Rules: Flood Elevation Requirements (2026)

Section 122-25(c) sets Monroe County's own elevation standard for at-grade residential detached accessory structures used only for parking or storage. 2. A variance under Section 122-15 can authorize a larger accessory structure, up to 1,000 square feet, but not beyond that ceiling. In coastal high hazard zones V, VE, and coastal A zones, an at-grade accessory structure cannot sit below an elevated building and is capped at 100 square feet. Every such structure must be anchored to resist flotation, collapse, or lateral movement from flood loads.

Below the base flood elevation plus one foot, the structure must be built of flood damage-resistant materials, and any mechanical, plumbing, or electrical systems, including plumbing fixtures, must be elevated to or above that same base flood elevation plus one foot line. Applications must include a nonconversion agreement under Section 122-11(i), which bars later converting the space to living area. Nonresidential detached accessory structures instead follow the Florida Building Code and ASCE 24 directly for elevation or dry floodproofing, per Section 122-25(d). Principal buildings within the scope of the Florida Building Code get their foundation and pile design from a Florida-licensed geotechnical engineer under Section 122-25(b), anchored into natural rock with a minimum 14-inch socket and 3-foot embedment.