The department provides services to owners and occupants in both existing and new buildings in the private sector through enforcement of the Buildings Ordinance. As regards existing buildings, the services provided include reducing dangers and nuisances caused by unauthorised building works and advertisement signboards; promoting proper repairs and maintenance of old buildings, drainage and slopes; considering and approving alteration and addition works; processing submissions under the simplified requirements and the household minor works validation scheme of the minor works control system; improving fire safety measures in buildings and providing advice on the suitability of premises for the issue of licences for specified commercial uses. As regards new buildings, the department scrutinises and approves building plans, carries out audit checks on construction works and site safety and issues occupation permits upon completion of new buildings.