The first phase of construction, foundation work covers everything from the first placement of the first piece of the foundation in the ground until the structure begins rising above ground level.

Foundation work does not include excavation. It begins, rather, when the first pile is planted in the earth, or when the first stone is laid or the first bucket of concrete is poured. In short, at least part of the structure must be fixed in its place on the site before this phase begins.

Installation of part of the structure separates foundation work from site preparation. Excavation alone prepares space for the foundation without yet putting a structural element in place.