Consilium Guides / Flood risk
How to check flood risk before buying a home
The fastest way to compare flood exposure between two places is a Consilium Compare report. It shows what share of each ZIP code sits in FEMA's high-risk, moderate, and minimal flood zones, side by side, for $1.99 at our launch price. Once you've narrowed it down, confirm the exact property's zone before you make an offer.
What a Consilium report shows you
- Flood-zone share for each ZIP: how much of the area is high-risk, moderate, or minimal, from FEMA's National Flood Hazard Layer.
- Both places side by side, so a difference jumps out instead of hiding in two browser tabs.
- Flood risk in context, next to rainfall, climate, and the other risks in the report.
For example, Realtor.com's #1 and #5 hottest ZIPs for 2026, Peabody and Westfield, Massachusetts, each have about 11% of their area in FEMA's high-risk zone. That's roughly three times the New Jersey pair on the same list, Montclair and Sewell, at 3% to 4%. Listing photos won't show you that.
What the flood zones mean
| Zone | What it means |
|---|---|
| A, AE, AH, AO | High risk. At least a 1% chance of flooding each year. |
| V, VE | High risk on the coast, with storm waves. |
| X (shaded) or B | Moderate risk, about a 0.2% chance each year. |
| X (unshaded) or C | Minimal mapped risk. |
| D | Possible but undetermined risk. The area hasn't been studied. |
A 1% yearly chance sounds small, but over a 30-year mortgage it adds up to about a 26% chance of at least one flood.
Why the ZIP-level view comes first
Comparing ZIP codes tells you which places carry more flood exposure overall, before you spend time on individual listings. It also shows where FEMA hasn't mapped much of an area, which is worth knowing too. Our report notes when that's the case.
Before you make an offer on a specific house
- Confirm the property's official flood zone with your agent, lender, or insurance agent. Your lender will check it anyway if a mortgage is involved.
- Ask the seller in writing whether the home has ever flooded or had a flood insurance claim. Disclosure rules vary by state.
- Get a flood insurance quote, even outside a high-risk zone. About a quarter of flood losses happen outside high-risk areas, according to the National Association of Insurance Commissioners.
- Ask whether the home has an elevation certificate. It shows how high the home sits relative to expected flood levels and can lower your premium.
FAQ
How do I find out if a house is in a flood zone?
Start with a Consilium Compare report to see how much of the ZIP code sits in high-risk zones. For the exact house, your lender or insurance agent will confirm its official FEMA zone.
Is flood zone X safe?
Zone X means moderate or minimal mapped risk, not no risk. Homes in zone X can and do flood.
Does homeowners insurance cover floods?
Usually not. Flood coverage is a separate policy.
For more on reading the flood section of a report, see How FEMA flood zones work. If a mortgage is involved, see when flood insurance is required. Agents: send clients a branded comparison.