The UK construction industry suffers from almost indeterminate losses of materials and plant through theft, vandalism and careless housekeeping. A large proportion of these losses are due to either inefficient or non-existent site security. This report considers where these losses occur and how to prevent them through effective planning and management. The report focuses on the largest material losses, plant theft, and the biggest risk, fire. Site safety, fire prevention and security should be considered together rather than in isolation as is current practice.