The first test property is a two-storey detached single family house located in Durham, North East England. This is a new build timber construction that meets Passivhaus standards. The house comprises entrance hall, living room, dining room, kitchen, office room, utility room, family room, bathroom, three bedrooms and en-suite and features and advanced thermal design to passive house standards for the external wall, floor, roof, windows and doors. Heating, whole house ventilation, solar PV and rainwater harvesting systems are also incorporated.