And sits on bedrock (for lack of a better term) of coral rock, not limestone. The Keys are atolls, which are basically really big coral reefs that are large enough to support buildings, roads, and people. Coral does not dissolve with water (if it did, there would be no coral reefs to dive down to).
So, yes, Virginia, there are basements in Florida. But they are few and far between and extremely pricey.
Coral is just limestone waiting to happen! 
Heh - we’d have to turn up the heat even in the house for you - we keep it nice and cool in here. 
Calgary deals with an overabundance of feathery ice crystals by ignoring them and hoping they’ll go away, but we’re working on that.
I’ve never actually lived in Florida, but I’ve had enough encounters with “cockroaches you can ride” while visiting my in-laws there to make me familiar with the beasties.
I have lived in Florida for over 15 years and have never seen a basement here, until I move to the West Palm Beach area for work. The bar I manage has a basement and we are located less than 500 ft from an open water way. It has flooded several times due to plumbing issues but nothing major. It’s the creepiest basement I’ve been in too.
North Carolina has a lot of contrasts. Here in southeast NC my realtor bragged, This house is 23 feet above mean high tide, so we’re on a virtual mountain here. No basement. All my previous had one, and I miss having one, but I can see where it’s impractical here.
I suspect it comes back to building codes and costs.
Way back in the early 60s we had a family friend who was an engineer. He was involved in building some houses in S. Wales on sand. The method they used was to build a concrete tank above ground, the size of the single story house, with an apron extending out at the top. Once this was in place, they vibrated the sand and the concrete sank under its own weight. This then became the foundation (and cellar) for the house
I have no idea if they are still there.
I am also an engineer, an oddly enough, your neighbor and I had the exact same thought - Florida basement = swimming pool!
Generally speaking, basements are built in climates where there are cold winters. The foundations must be dug deep enough to get below the frost line, so as to not crack when the soil freezes and expands. Usually, the foundation must be about 36 inches deep, but digging little deeper gives you extra living space for very little added cost…
In Florida, there is no freeze-thaw cycle, so basements are not common. If fact, they are very difficult to build, even if you built the foundation to be perfectly water tight so it didn’t flood. A perfectly sealed basement would get pushed up by the water table, unless properly anchored. Without the complex anchoring, your house would essentially “floating” like a boat on the underground lake that is the water table!
We had a basement in the house I grew up in, but it was only partly underground. I guess the house had been built into a hill(the driveway was really steep). We had doors to the outside on one side, and on the opposite it was clearly under ground. That house was built in the 20’s I think. My house now is not far away and perhaps older but no basement. This is in TN.
My sister had a townhouse in Minnesota that was built on concrete slab. Are such buildings going to self-destruct? Based on the above, it would seem they’d need basements.
In northern climes, a slab foundation has to have piers underneath it that extend below the frost line. Otherwise, the frost heave will crack the slab. It is sometimes done for stylistic reasons, but excavating a basement is not much more expensive.
I have a split level house in Minnesota. Half of it has a basement, half is on slab.
As long as sufficent (numbers and depth) pilings are installed, your sister is fine. My house is 45 yrs old and doing just fine.
Hi! We just bought a 1920 Bungalow on Lake Wailes in Lake Wales and it has a basement. Our house doesn’t even sit on the high test part of the land around the lake. A few houses here have them. Also, a few buildings as well like the Post Office, the original Town Hall/ jail just to name a few. When I came to our house with our realtor I expected to find a closet and not a stairway to the basement. I’m from Ohio but have been here 30 years my husband had never been in a basement and now he owns one. It’s odd because our house is wood frame but that central part is stone/concrete and it looks to have had an outside entrance at some point that got blocked up. The previous owners that lived here 30 years said it has never flooded and neither has the lake not even during the 2004 hurricanes. Their is a picture of our house in a book about Lakes Wales.
It’s often said in life (by those who need to say so) that size doesn’t matter. I’ve experienced the Canadian north near the end of the tree line, where the temperature dips to -40 (can’t remember if that was Celsius or Fahrenheit). There are mosquitos - normal sized ones - and horseflies, like a slightly oversized housefly but a bite that hurts! But the absolute worst are the tiny blackflies. They all come in clouds that darken the sun (sort of) and keep you flailing non-stop to no avail. Legend has it that settlers who tried to use horses up north gave up because the horses went mad from all the biting insects - particularly blackflies. The only saving grace is the preponderance of dragonflies, some huge, that dine on the little munchers.
(I went to the Serengeti once, and tsetse flies look like houseflies, same size but have the bite like a big horsefly).
I’ve been in quite a few old houses in Toronto and elsewhere. The style around 1900 was that basements were built but not used for much; I assume because radiator steam heat was the standard, so there was no forced air circulation. As a result, basements were less practical things. In the days before natural gas, too, the coal furnace was down there. Conveniently, coal could be poured from the road level down a chute into the basement coal bin and shoveling coal into the furnace was a regular chore. No point in putting a rec room next to the place where everything got filthy from black dust. So all the Victorian basements I remember were unfinished - rock/brick walls, plenty of pipes, expose joists overhead and very low headroom. In early days, insulation was less of a concern. Tiny basement windows were often single pane. When people tried to finish these once gas furnaces were installed, the low headroom was always a problem.
(I recall it was about 1964 that our school from the 1920’s was converted from coal to gas)