And - putting some insulation under the slab can easily keep it "room temperature" as it absorbs the heat in the room and acts as a giant thermal mass. Easy to get passive heating if you so desire (and manage, in Florida especially)

The pipe thing is overblown. In the RARE event it happens - do as David recommends or run larger supply lines and if there is a leak, you fish smaller diameter in there.

Crawl space houses, once common, have largely been surpassed by better insulated, higher quality slab on grade foundations, or in the case of areas where freezing conditions require foundations and foots at great depth, partial or full basements. The risk of piping leak and replacement in a slab on grade is greatly over-rated.

David Carey- yes, I have thought of double piping using Pex- at direct runs, not manifolds. I will do so also for potential outside electric.l lines that may run under driveway/sidewalk . Thx. Jannicone and Virgil- For meb I am very wary of slabs because the trouble and cost of a leak in slab already happened to me! IF I go one storey I will use the double wall/Pex- that was already on the list. I will add the under/insulation to list thank you.

Every region and location may be better suited for a particular type of foundation. FL is prone to hurricanes and we in WA are prone to earthquakes. Apart from code compliance, choice of foundation should primarily match the region, budget contraints, heating and cooling requirements, not forgetting longivity and ease of maintenance. A slab, usually most economical, can be constructed to provide a warm feel depending on insulation material and substrate below slab. I would firmly recommend a heated slab, it would be worth the investment.

Crawl space offers a host of possibilites for plumbing, ductwork, insulation, heating etc. etc. Depending on size of the house and how you envisage using a crawl space, will dictate crawl space foundation style, stem walls & posts, post and pier, pier and beam etc. some cost more than others; a final decision should be left to a structural engineer.

I went way over the top with the foundation of our home currently under construction, but that's another story.

I'm interested in this subject as I have only ever lived in houses with crawl spaces, which I am very comfortable with. The thing that concerns me most about slab houses is that I MUST have site finished oak hardwood floors and I don't know how well they will work on slab foundations.

You can do hardwoods on a slab.

I've owned crawlspace and basement on slab. Slab is easier to make tight and cheaper. But absolutely region plays a role.

In our part of SC, it's a mixed bag, with older homes mostly being on a crawand ranges from 60 to 75 F.l space, with a few basements thrown in. Most newer homes seems to be slab. The crawl spaces aren't insulated or conditioned, so every cold snap brings a rash of frozen pipes.

We built on a full basement because it fit the topography of our land. A slab wouldn't have worked without enormous amounts of fill, and a 'crawl space' would have been 6' high anyway. After living on a slab for 30 years in FL, I strongly prefer a basement or properly constructed crawl space. I like the slight give of a suspended floor; slab floors are hard on the back and feet. I also like to be able to move plumbing without a jackhammer. If you put the HVAC ductwork in the attic, the attic should be a conditioned space.

In our current home in SC, we have a full, insulated, walk-out basement. I went to extraordinary measures to make sure that it will stay dry. With a little finish work, we can double the size of our house. Because of the ICF construction, it is fully insulated and ranges from 60 to 75 F. year-round with no HVAC at all.

There is nothing wrong with a slab on grade for your first floor in the south, provided it is designed and constructed correctly. Piping shouldn't be a big concern if the supply piping is PEX and the waste/drain/vent is PVC or CPVC.

Thank you all. Seems either way is acceptable providing you prepare properly. Charles Ross- I agree with you- my back is not getting any younger. I love basements! Especially walkouts. Cooler in summer warmer in winter. Storage for seasonal changes.