Flood insurance due diligence, before you write the offer.

The fastest path is a FEMA flood zone lookup by address — free, live, and takes about 20 seconds. If the parcel returns Zone A, AE, V, or VE, insurance is mandatory with a federally-backed mortgage and typically costs $1,500–$40,000/year depending on the zone. Verify with a FEMA-listed insurance agent before closing, but the zone check alone is enough to price the decision at the LOI stage.

Nothing, for a live zone check. Buildability’s flood-zone tool is free and covers every U.S. address using official FEMA National Flood Hazard Layer (NFHL) data. If you want a defensible written record for your file — with the base flood elevation, LOMA/LOMR eligibility flags, and every other factor a lender or committee will ask about — a full Buildability report is $99 (sliding to $79 at volume) and includes the flood work alongside zoning, seismic, wildfire, and soil.

Zone X (minimal risk): $400–$800/year if purchased voluntarily. Zone A/AE (100-year floodplain): $1,500–$5,000/year, mandatory with a federally-backed mortgage. Zone VE (coastal high hazard): $8,000–$40,000/year, mandatory with strict construction standards. Ranges are NFIP historical bands; a Risk Rating 2.0 quote from your agent is the binding number.

Yes. On a $400,000 land buy, a $12,000/year VE-zone premium is roughly 3% of purchase price annually — often more than property tax. Over a 10-year hold, that is $120,000 of pre-tax carry that has to come out of the deal math. Verifying the zone before LOI moves that number into your offer, not your surprise column.

A Letter of Map Amendment (LOMA) is FEMA’s process for removing a specific structure or parcel from a Special Flood Hazard Area when a licensed surveyor certifies it is above the base flood elevation. Cost: $500–$5,000. Timeline: 60–90 days. The Buildability report flags parcels that appear to be LOMA candidates so you know before spending on a surveyor.

FEMA maps are the legal standard for insurance and lending decisions, but they are periodically revised — climate change, new development, and improved topographic data drive updates every 5–10 years per community. Buildability queries the National Flood Hazard Layer live at run time, so you always see the current designation, and the report timestamps the query so you can point to the exact vintage in your file.

Roughly 25% of NFIP claims come from properties in Zone X — the "minimal risk" area outside the 100-year floodplain. This is why lenders in some states have started requiring flood insurance disclosures even outside SFHAs, and why serious buyers verify the zone regardless of what the seller volunteers.

Twice. First, before you write the LOI — a free zone check tells you whether flood insurance is a factor at all, and roughly what it will cost. Second, before closing — a full report locks in the zone designation, BFE, LOMA candidacy, and monitoring going forward. Doing it once, late, is how buyers get surprised at underwriting.

Yes — all 50 states. FEMA’s NFHL covers every U.S. address, and Buildability queries it live for every parcel. No pre-loading required, no geographic gaps.