All UK bat species are legally protected, and their roosting sites have strict legal protection even when bats are absent. Bats rely on a network of roost sites for maternity, hibernation, and day roosts, making roost conservation critical.
Bats face significant welfare threats from roost disturbance and destruction, often inadvertently through building renovation, timber treatments, and development. Loss of maternity roosts mid-season can result in abandonment of young, causing mortality. Hibernating bats disturbed from winter roosts may be unable to find alternative sites and die from exposure or starvation. The obligation to conduct bat surveys before building work protects both individual bats and the continuity of roost networks essential to population survival. Where work is unavoidable, mitigation roosts installed before disturbance allow populations to continue.