Abstract: A method of operating an environment management system within a building, comprises: monitoring appliance usage within the building by monitoring two or more utilities and measuring one or more characteristics relating to each of the utilities to provide an output signal representative thereof; monitoring for changes in the state of each of the output signals at predefined time intervals; combining data from the output signals from each utility, to identify one or more patterns of appliance usage; comparing the identified pattern of appliance usage with stored patterns of appliance usage associated with individual occupants of the building to identify an expected pattern of future appliance usage; and operating the environment management system to control the environment in the building in accordance with the identified expected pattern of future appliance usage.