A building management system improves the regulation and controls the functioning of appliances (41, 42, 51), such as luminaires, window blinds and heating equipment in a building. The appliances are connected via a communication bus (20) to a control system (10), which performs the automatic regulation and control. To avoid rewiring the bus (20) every time that changes are made to the arrangement of the appliances and/or the lay-out of the building, transponders