Understanding Some Tricky Real Estate Terms in the Florida Keys

Buying or selling a home in the Florida Keys comes with its own language. Locals and real estate pros throw around terms like “below flood,” “pre-FIRM,” and “legal non-conforming” like everyone knows what they mean — but let’s be honest, they can be confusing if you’re not in the business. So let’s break them down in plain English:

“Below Flood”

This one pops up a lot in older homes. When we say a property is “below flood,” we’re usually talking about the lowest living level being below the Base Flood Elevation (BFE). That’s the height FEMA says floodwaters might reach during a major storm.

So if a home’s downstairs living area is below that line, it’s considered “below flood.” This matters because it can affect insurance rates and how the home can be used in the future. Many homes built before floodplain regulations were established still have these lower levels — sometimes used as living space, even if they technically shouldn’t be.

“Pre-FIRM”

This stands for Pre-Flood Insurance Rate Map. In the Keys, that typically means the home was built before the first official flood maps were issued — usually before 1975.

Why does that matter? Homes built pre-FIRM weren’t required to meet today’s stricter elevation and construction rules. That can impact flood insurance costs and how FEMA views the property. Some pre-FIRM homes have been “grandfathered in,” but buyers should always understand what that means for insurability and future renovation rules.

“Legal Non-Conforming”

This is a fancy way of saying: “It was legal when it was built, but the rules have changed.”

For example, a home might have a downstairs apartment that was perfectly legal under old codes, but wouldn’t be allowed under today’s zoning or flood regulations. Because it was built legally at the time, it can often stay — but if it’s damaged or remodeled, current codes may apply. It’s kind of like a “hall pass” from the building department — but with conditions.

Final Thoughts

These terms aren’t meant to scare you off — they just highlight how unique real estate in the Florida Keys can be. From older conch homes to stilted waterfront getaways, every property has a story. As a longtime Keys local and Realtor, my job is to help you understand exactly what you’re buying (or selling), so there are no surprises down the road.

Got questions about a property you’ve seen? I’m happy to help decode the fine print — and make sure you’re in the know.