Plain-Pied is a French real estate term found in property advertisements meaning that a property (normally a house) is built at street-level. There are no steps into the property and there is no basement or cellar. It can also mean that the property is one storey or is a detached bungalow. As with any common expression the meaning can very slightly.
Plain pied also has other meanings outside of real estate.
Here is a video illustration of a plain pied home.
