In a conventional electrical installation system each function needs its own cable and each control system a separate network. In contrast the instabus EIB* enables sensing, switching, control, monitoring and signalling of all functions and sequenses via a single common line. The power supply can be led directly to the loads without making any diversions. The common line comprises a two-core cable and bus compatible devices. Sensors (light switches, brightness/temperature sensors, air-speed indicators etc) and actuators (e.g. luminaires, ventilators and drives) can all communicate with one another without the need for a control centre. In addition to to the large reduction in wiring (30% copper), the installation system can be easily set up, commissioning is much faster than traditional BMS, and is highly versatile. Taking a ground-up approach rather than a top-down one means that the system can be easily extended to meet changing demands of the building or group of buildings.In addition to a large reduction in wiring and consequent costs, the installation bus system can be easily set up. Being a peer-to-peer distributed system means that each device talks directly to other devices. This means that response is fast and can be applied in situations where dynamic control is important.