What is pilotis?
Pilotis are columns that raise a building clear of the ground so that the ground floor remains wholly or largely open. The word is French and literally means “piles”. The term is inseparable from Le Corbusier, who made pilotis one of his five points of a new architecture: the building is lifted off the ground, the ground runs on beneath it, and the facade is freed of its load-bearing role.
Why put a building on legs
- Continuous ground. The space beneath stays usable as a passage, covered area, parking or public space.
- View and light. The living floors rise above their immediate surroundings.
- Structural logic. With a column frame the facade carries nothing, allowing ribbon windows and a free plan.
- Water. In flood-prone areas and when building over water, raising the volume is a practical rather than an aesthetic decision.
Building physics to watch
A floor on pilotis is an exposed floor: it faces outside air, not a crawl space or the ground. That has serious consequences.
- Insulate more heavily. A floor over outside air loses far more heat than a floor over a crawl space. Expect to exceed the minimum requirement for a ground floor.
- Thermal bridges at the columns. Exactly where the column passes through the floor, an unbroken concrete thermal bridge forms. Interrupt it, or account for the column explicitly in the thermal detailing.
- Freezing services. Water and heating pipes in or below a floor over outside air can freeze; run them on the warm side of the insulation.
- Wind nuisance. Wind accelerates beneath a raised building; on tall buildings that is a study in its own right, not a detail.
- Fire resistance of the columns. Free-standing columns carrying an entire building must meet their own fire resistance requirement — with steel that almost always means encasement or an intumescent coating.
Applications
The classic examples are Le Corbusier’s Villa Savoye and Unité d’Habitation. In current practice the principle shows up in housing blocks over a parking deck, schools with a covered playground, cantilevered building elements, and homes on floodplains or over water.
Related terms
- Column
- Frame construction
- Thermal bridge
- Free plan
- Cantilever
Want to learn more about construction terms? Visit our knowledge base at fredsdiyplans.com.