The Medieval Bishops Palace in Lincoln is home to colonies of Natterer’s bats. Structural works to protect the historic floor and to provide increased public usage of the Palace had to be carried out without affecting the bat colonies. FPCR pinpointed the areas used by hibernating bats to obtain a DEFRA licence for the works to be undertaken. Close liaison with the building team enabled works to be developed without adverse effects. FPCR are providing a monitoring role throughout the construction works. Mitigation included the provision of hibernation and roost bat boxes.