The invention provides a control arrangement and corresponding method for intelligent control of at least one energy consuming device within a building. The control arrangement comprises a switch component for controlling a first energy consuming device such as a lighting device, heating, ventilation or security device; and/or a computer- implemented control component for intelligently controlling at least one further energy consuming device, such as a heating, air conditioning, ventilation or security apparatus. The switch component and/or the control component are provided within a housing which is mounted within or interfaced to a pattress or wiring box during use. The control component comprises a microprocessor and suitably arranged software configured to receive sensor data obtained from one or more sensors provided in or on the housing, and/or process the sensor data to enable the system to intelligently control the at least one further energy consuming device. The system is configured to build a model of a building occupant's behaviour so that the energy consuming devices can be controlled more efficiently and intelligently. The invention is simple and easy to install because it replaces an existing light switch or thermostat.