A method of configuring a site, the site comprising a plurality of devices (11 - 23), the plurality of devices (11 - 23) comprising a plurality of site controllers and a plurality of sensors and a plurality of appliances, the method comprising the steps of: selecting a first device (11 - 23) from the plurality of appliances and/or from the plurality of sensors; loading a device database, the device database comprising descriptor data for the plurality of appliances and/or for the plurality of sensors; using the device database to produce first descriptor data for the first device (11 - 23), the first descriptor data describing one or more technical properties of the first device (11 - 23); selecting a second device (11 - 23) from the plurality of appliances and/or from the plurality of sensors; using the device database to produce second descriptor data for the second device (11 - 23), the second descriptor data describing one or more technical properties of the second device (11 - 23); loading an ontology database comprising a set of rules applicable to the first device (11 - 23) and to the second device (11 - 23), the ontology database determining relationships between devices to be configured; producing relationship data indicative of a technical relationship between the first device (11 - 23) and the second device (11 - 23) by applying at least one of the rules of the set of rules of the ontology database to the first descriptor data and to the second descriptor data; selecting a third device (11 - 23) from the plurality of site controllers based on the technical relationship between the first device (11 - 23) and/or the second device (11 - 23) as indicated by the relationship data; producing a first set of configuration data based on the relationship between the first device (11 - 23) and/or the second device (11 - 23) as indicated by the relationship data; producing a second set of configuration data based on the relationship between the first device (11 - 23) and/or the second device (11 - 23) as indicated by the relationship data; producing a third set of configuration data based on the relationship between the first device (11 - 23) and/or the second device (11 - 23) as indicated by the relationship data; transmitting the first set of configuration data to the first device (11 - 23); transmitting the second set of configuration data to the second device (11 - 23); transmitting the third set of configuration data to the third device (11 - 23); applying the first set of configuration data to the first device (11 - 23); applying the second set of configuration data to the second device (11 - 23); and applying the third set of configuration data to the third device (11 - 23). selecting a first device (11 - 23) from the plurality of appliances and/or from the plurality of sensors; loading a device database, the device database comprising descriptor data for the plurality of appliances and/or for the plurality of sensors; using the device database to produce first descriptor data for the first device (11 - 23), the first descriptor data describing one or more technical properties of the first device (11 - 23); selecting a second device (11 - 23) from the plurality of appliances and/or from the plurality of sensors; using the device database to produce second descriptor data for the second device (11 - 23), the second descriptor data describing one or more technical properties of the second device (11 - 23); loading an ontology database comprising a set of rules applicable to the first device (11 - 23) and to the second device (11 - 23), the ontology database determining relationships between devices to be configured; producing relationship data indicative of a technical relationship between the first device (11 - 23) and the second device (11 - 23) by applying at least one of the rules of the set of rules of the ontology database to the first descriptor data and to the second descriptor data; selecting a third device (11 - 23) from the plurality of site controllers based on the technical relationship between the first device (11 - 23) and/or the second device (11 - 23) as indicated by the relationship data; producing a first set of configuration data based on the relationship between the first device (11 - 23) and/or the second device (11 - 23) as indicated by the relationship data; producing a second set of configuration data based on the relationship between the first device (11 - 23) and/or the second device (11 - 23) as indicated by the relationship data; producing a third set of configuration data based on the relationship between the first device (11 - 23) and/or the second device (11 - 23) as indicated by the relationship data; transmitting the first set of configuration data to the first device (11 - 23); transmitting the second set of configuration data to the second device (11 - 23); transmitting the third set of configuration data to the third device (11 - 23); applying the first set of configuration data to the first device (11 - 23); applying the second set of configuration data to the second device (11 - 23); and applying the third set of configuration data to the third device (11 - 23).