As a result of Subtask A of the FC+COGEN-SIM project [11], standard European and Canadian non-HVAC Electric Load and domestic hot water profiles have become available. The European non-HVAC Electric Energy Consumption Profiles of this study which have been suggested as “a good first estimate of domestic electrical energy consumption profiles for many European countries” are based on the UK domestic profiles monitored by EETS Ltd and the Welsh School of Architecture [12]. Using this data to simulate the internal gains due to appliances and lighting for the Welsh housing stock can therefore be considered the most accurate and realistic approach available for this purpose. For the domestic hot water consumption the Annex 42 report refers to two studies which suggest 116 litres per household per day as an average daily DHW consumption, based on a 45°C rise, for the UK. Therefore the energy required for the daily draw off of DHW for these models is assumed to be 6.07 kWh.