All UK bat species and their roosts are legally protected, but building works and development continue to destroy roost sites, requiring careful survey work and mitigation.
Bats displaced from roost sites during breeding season may abandon dependent pups, causing pup starvation. Roost sites used for decades provide stable temperature and humidity conditions that alternative sites may not match. Building work during bat hibernation can disturb individuals causing energy expenditure that proves fatal if fat reserves are insufficient. Roost loss affects entire local populations of species with low reproductive rates.