Deep excavation is excavation that goes down more than 4.5m (or 15ft) deep into rock or soil.

Excavations can range from shallow to deep and can be general or focussed. The depth of an excavation is dependent on the requirements of the excavation that is being carried out. An example of shallow excavation would be for laying electrical wires whereas a deep excavation would be for the foundations of a large office or housing block. Typically, shallow excavations are defined as being up to a depth of 1.5 metres. Deep excavations are defined as being deeper than 7 to 8 metres.

Deep excavations are much more difficult to plan than shallow excavations, and they require much more time and resources. Deep excavations should only be conducted by trained and skilled professionals, such as Renaissance Infrastructure.