The evaluation of a site takes place during the proposal stage of a development. The purpose is to supplement the desk-based data, in order for the local authority to make a fully-informed decision on whether to grant consent, and what conditions should be attached to the planning permission.

Evaluation seeks to understand more about known archaeological features, assessing their date, extent, character and preservation. It is also used to investigate apparently ‘blank’ sites, to determine whether or not they are genuinely devoid of archaeology. (Often a site has no known archaeology for the simple reason that it has never previously been studied).

Evaluation can take various forms. Most commonly it is involves the machine-excavation of trial-trenches, examining a small percentage of the overall development site. Other forms of evaluation include detailed walkovers or systematic field survey (artefact collection), test pitting and augering.