All UK bat species are legally protected. Disturbance to roosts — including during building renovation, tree felling and construction — is a significant welfare threat even when accidental.
Bats sealed into roost spaces during building work die from dehydration and starvation within days. Maternity roost disturbance during summer months can kill entire cohorts of pups in a single season. The Bat Conservation Trust provides guidance on planning bat surveys before any building work or tree removal near known roosting sites. Building regulations require bat-friendly mitigation when roosts are affected by development.