This document has been written for Clients and their professional technical advisers in the consturction industry. It aims to raise their awareness of the importance of ground, and highlights the consequences of inadequate site investigation: escalating cost and late completions.Inadequate site investigations can arise from a lack of awareness of the hazards associated with ground, inadequate focus of finance, insufficient time and a lack of geotechnical expertise. Case histories are used to illustrate the consequences of inadequate site investigation.