It may be a planning condition that a watching brief is carried out during building or breaking ground. This will involve at least one archaeologist being present to monitor work and record any archaeological remains or elements. With smaller, less-significant remains it may be possible to investigate and record them in the space of a few hours or days. However, important discoveries may require extensive investigation, which will delay development unless a rolling programme of works is in place to allow for this eventuality.
The watching brief may be required to be in place for the full duration of the project or only on occasions. Where it is considered that there is little chance of archaeology being uncovered the watching brief is a cost effective methodology but unexpected discoveries may warrant a further phase of work to satisfy planning conditions.