A floating foundation is the foundation of a building that does not use footings. It is a poured cement slab that has two deep edges that go just below the frost line in northern climates. The foundation actually does float on the earth and moves as temperatures compact and expand the soil. It is very common in garage floors and mobile home slabs, and in many parts of the world, it's simply referred to as a slab foundation.
Foundations in coastal areas must be constructed such that the top of the lowest floor (in A zones) or the bottom of the lowest horizontal structural members (in V zones) of the buildings are elevated above the BFE, while withstanding flood forces, high winds, erosion and scour, and floodborne debris.
In a typical floating foundation, the plumbing and electrical lines are fastened to the slab by simply running them through the floor as it is poured. This means that the plumbing, drainage, and electrical lines must all be completed prior to pouring the foundation. In many cases, it is a much more affordable method of building than using a footing equipped foundation, but it can lead to very expensive repair bills if the plumbing requires work in the future. In warmer climates, the floating slab is much more friendly to homeowners as it does not flex too much because there are fewer extreme changes in temperature. It also helps to cool the structure, as the foundation's contact with the ground draws cool temperatures through the concrete and disperses them throughout the building.