Our house has been built to the Passivhaus (Passive House) standard. Instead of thermal mass and cross ventilation, the house is standard stumps and timber frame construction; the whole building envelope is carefully wrapped and insulated, with careful attention to airtightness. Windows are high-performance double glazing with no thermal breaks. A heat retention ventilation (HRV) system circulates air, ensuring the air is fresh. The living spaces face north with large windows for passive solar gain, and a pergola will support a deciduous vine for summer shading.