foundation work begins

Foundation work on a structure begins with the permanent physical installation of the first piece of its supporting structure in the earth. This event marks the beginning of the construction phase.

Excavation removes earth but does not by itself install a supporting element. Its start can therefore precede the start of foundation work.

A groundbreaking ceremony can occur before or after physical work begins. The foundation milestone is established by the first permanent supporting element, independently of the ceremonial date.