There are 17 species of bats known to breed in the UK. Bats and their roosts are protected year-round, although their use may be purely seasonal. 
Initial assessment can be conducted at any time of year, looking for evidence of or potential for use as a bat roost.  
If the structure is found to be suitable, then Nocturnal surveys will be required. These must be conducted between May and August in appropriate weather conditions. 
If the proposed works are considered to risk impact on bats then Mitigation and Compensation methods will need to implemented. If a roost is to be altered or destroyed, a licence will be required which involves application to the appropriate Government body.  
All of our Ecologists are full members of the Chartered Institute of Ecology and Environmental Management and hold Natural England CL18 licences. 
Dr Angold also holds the Low Impact licence for Bats, for works that impact below a certain threshold. This will outline the timing and methods of works, mitigation and/or compensation measures to be undertaken and any monitoring required. 
AMPA Associates are able to provide a full service taking you through this process from start to finish.