Bats are always found in heritage buildings in Hong Kong, especially the vernacular Chinese-style buildings. This is because the natural environment which suitable for bat roosting is reducing and the structure and low disturbance of the heritage buildings are suitable for bats to roost. As conservation of heritage buildings arouse more and more attention in recent years, there are more and more conservation work projects in heritage buildings too. When planning conservation work in a heritage building with the existence of bats, what are the issues to be concerned? Since bats are protected by the Wild Animals Protection Ordinance (Cap.170), it will be an offence if works to be carried out which will hurt bats and destroy their roosts. However, sometimes conservationists seem face a difficult choice in keeping the bats or carry out the conservation work. The work may impose adverse impacts to bats such as destroying their roost and disturbing them. But keeping the btas in the heritage buildings without the conservation work, the building may become dilapidated or even collapse. As there is no comprehensive bat mitigation guideline for conservation work for heritage buildings in Hong Kong. Although there are some guidelines available in Europe and USA, are they applicable in Hong Kong? The aim of this dissertation is to provide a preliminary guide for building professionals/ conservationists to handle the bat issue when planning conservation work to heritage buildings with bat existence. The facts of bats in Hong Kong is studied then followed by the examination of mitigation measures proposed by Natural England with assessments and adjustments to fit the use in Hong Kong. Two local cases are studied and evaluation of the bat mitigation has been carried out. Finally, some points to note when carrying out conservation work in heritage buildings in Hong Kong have been discussed. / published_or_final_version / Conservation / Master / Master of Science in Conservation