The decision of to build a home on a slab or over a conventional crawl space is not merely a matter of preference. Many factors go into making this “foundational” decision. Here are a few points to consider:
Geography and Climate Considerations
Crawl space foundations are recommended for dryer climates since moisture can accumulate there, and they are also recommended in flood-prone areas. A house with a raised crawl space is less likely to flood in areas where rising water is a real possibility.
A concrete slab foundation is better in a wet, but not flood-prone climate where moisture might accumulate within a crawl space. The vapor barrier that lies beneath the slab will prevent mold growth from entering the home.
A slab can help insulate a home by eliminating the free-flowing air under the floor that is present with a crawl space. This can save on heating and cooling bills. Even a well-insulated floor cannot help a crawl space match the energy savings of a slab foundation since outside air still circulates beneath the subfloor, causing temperature fluctuations in the home.
A concrete slab makes for a hard surface to stand and walk on. Even the best floor coverings will not make the floor as forgiving as a floor built over a crawl space. These floors, or at least the subfloors are usually wood. This makes them more comfortable as walking surfaces.