The rule determines whether a flood-zone home must be elevated or brought into compliance.
How it works
- Your local floodplain administrator compares repair or improvement cost with the structure's market value
- At 50% or more, the home must meet current floodplain rules
- A few Tampa Bay governments use a lower threshold: St. Petersburg and unincorporated Pinellas County use 49%
- Market value means the structure only, not the land
- Since 2025, Florida law (s. 163.31795, F.S.) bars local governments in the NFIP from using cumulative substantial-improvement periods, so each project is generally evaluated on its own