Stilt houses or pile dwellings or palafitte are houses raised on piles over the surface of the soil or a body of water. Stilt houses are built primarily as a protection against flooding, but also serve to keep out vermin. The shady space under the house can be used for work or storage.

Houses where permafrost is present, in the Arctic, are built on stilts to keep permafrost under them from melting. Permafrost can be up to 70% water. While it's frozen, it provides a stable foundation. If heat radiating from the bottom of a home melts the permafrost, however, the home will go out of level, and start sinking into the ground. While other, more elaborate means of keeping the permafrost from melting are available, raising the home off the ground on stilts is one of the most effective ways.

History

In the Neolithic and Bronze Age, stilt-houses settlements were common in the Alpine and Pianura Padana (Terramare) region. Remains have been found at the Ljubljana Marshes in Slovenia and at the Mondsee and Attersee lakes in Upper Austria, for example. Early archaeologists like Ferdinand Keller thought they formed artificial islands, much like the Scottish Crannogs, but today it is clear that the majority of settlements were located on the shores of lakes and were only inundated later on. Reconstructed stilt houses are shown in open-air museums in Unteruhldingen and Zürich (Pfahlbauland). In June 2011, the prehistoric pile dwellings in six Alpine states were designated as the UNESCO World Heritage Site. A single Scandinavian pile dwelling, the Alvastra stilt houses, has been excavated in Sweden.