1. A controller for controlling one or more sources of a utility to provide the utility into a space occupied by one or more users, the controller comprising: motion detection logic configured to process an input from a first sensor to detect motions of a user in said space, and to detect that the motions correspond to predetermined gestures performed by the user, the gestures being performed from different respective positions within said space; positioning logic configured to process an input from a second sensor to detect the respective position from which each of said gestures was performed by the user; control policy selection logic configured, based on an association associating each of a plurality of discrete control policies with a respective combination of predetermined gesture and positional demarcation within said space, to select different ones of the control policies associated with the detected gestures performed from each of the different detected positions in dependence on the respective detected position, each control policy defining a respective response of said utility to the respective associated gesture; and command logic arranged to control the one or more sources to provide the utility in accordance with the respective response of the selected control policy, wherein the detected position comprises at least a directional orientation of the user from which he or she performed the detected gesture, and the positional demarcation associated with one, some or all of the control policies comprises a respective directional demarcation; the control policy selection logic being configured to select said one of the control policies that is associated with the detected gesture and with the directional demarcation within which said directional orientation is detected to fall.