Spring Hill, FL Accessory Structures: Garage Conversions (2026)

A garage-to-living-space conversion in Spring Hill is regulated as a structural alteration and a change of occupancy classification under the Florida Building Code 7th Edition (2020) as administered by the Hernando County Building Division at (352) 754-4050. A building permit is required; an electrical permit is required for any added or modified wiring; a mechanical permit is required for HVAC modifications; and a plumbing permit is required for added sinks/bathrooms. The converted space must meet FBC residential minimums: ceiling height (R305) — 7 ft minimum; egress windows in sleeping rooms (R310) — 5.7 sq ft net openable, 24 in minimum height, 20 in minimum width, 44 in maximum sill height; smoke alarms (R314) in each sleeping room, hallways, and on each level; carbon monoxide alarms (R315) outside each sleeping area; FBC Energy Code insulation values; and Florida wind-load requirements (Hernando County ranges 130-140 mph basic wind speed depending on coastal proximity). If the converted space includes a complete kitchen (sink + range + refrigerator + cabinets) and a separate entrance, the conversion creates an Accessory Dwelling Unit and triggers Hernando County's Appendix A ADU standards: attached only (already satisfied — the garage is part of the home); ≤50% of the primary dwelling's gross habitable square footage; owner-occupied principal residence; one ADU per lot maximum; architecturally consistent with single-family character; entrance through the main door or on the side/rear of the principal structure (not a separate street-facing front entrance); not sold separately; and intended for non-paying family guests rather than tenants. The conversion must not reduce the off-street parking below the minimum required for the principal dwelling under the zoning code — Hernando County requires 2 off-street parking spaces per single-family dwelling. If the converted garage was your only off-street parking, you must add replacement parking on the driveway, an extended driveway pad, or a paved parking pad. Floodplain compliance under Hernando County Code Chapter 9 is required for any conversion in a FEMA Special Flood Hazard Area (large portions of Spring Hill near the Weeki Wachee River, lakes, and conservation areas are Zone X or AE). Termite inspection and treatment certification are required by the FBC.