This page provides general practical guidance and does not replace project-specific legal, engineering, planning, ecological, asbestos or waste advice.
The short answer
Consider ecology early where a structure could provide habitat or where there is evidence of bats, nesting birds or other protected species. Bats and their roosts — including breeding sites and resting places — are protected under the Wildlife and Countryside Act 1981 and the Conservation of Habitats and Species Regulations 2017. The absence of visible bats does not establish that demolition can proceed; a roost may be present without obvious signs. Wild bird nests are protected while they are being built or used, whenever that occurs — protection is not limited to a fixed nesting season, and working outside the usual breeding season is not automatic clearance to proceed. The need for a survey or specialist advice depends on the individual site and proposed work — it cannot be determined from a photograph alone.
Why it matters
Ecological constraints can affect timing and method. Initial ecological assessment can often begin throughout the year, but seasonal limitations must be recorded and further surveys may be needed at suitable times. A roost found after the programme has been fixed can cause significant delay. For birds, a nest found in use during work can require work to stop until the nest is no longer in use. Early assessment allows any constraints to be built into the programme rather than discovered once mobilisation is planned.
Information that may be needed
Site photographs, information about the structure, evidence of wildlife and any previous ecological reports may be useful. A preliminary ecological appraisal (PEA) or bat survey report, where one exists, should be shared before the scope is finalised.
What can affect the scope
The building type, condition, location, visible evidence, season and proposed work can all affect the need for further assessment. Older buildings, buildings with roof voids, and structures in or near woodland, hedgerows or water are more likely to require assessment.
When specialist input may be needed
A suitably qualified ecologist is required where the site or evidence indicates a potential issue. A preliminary ecological appraisal (PEA) can identify whether further surveys are needed and what timing constraints apply. Where a European Protected Species licence is needed, this must be obtained before work begins. Project-specific decisions about survey requirements and timing should be directed to a competent ecologist.