Passive House Buildings
During the past 20 years, there has been a great deal of research on energy efficiency in construction, and one of its most important outcomes is the passive house standard.
The passive house standard requires, for instance, not exceeding a specific value of primary energy (net heating amount of 120 kWh/m² annually) in the total operation of a building including energy used for activities conducted within it.
In order to achieve this in our climate, a building must normally be very highly insulated (approx. 25-35 cm thick), use triple-glazed windows, and have an airtight envelope tested in the “blower door” method. It must minimize thermal bridges, have a highly efficient ventilation system (0.3 W/m³) with heat and moisture-recovery capability, and summer thermal protection, such as exterior shutters, as well as adequate ventilation devices and a thermal storage mass. Beyond this, the energy used for hot water and lighting, as well as household appliances, computers, and other uses, must be kept at a minimum. In addition to its low level of energy consumption, this standard also significantly improves user comfort.
Obviously, the issue of energy efficiency does not stop at the building, which is why considerations regarding the building site and access to public transit must also become part of the process of achieving of high energy efficiency standards.
Since 95% of building projects involve existing structures, applying this passive house standard to renovations as part of a comprehensive strategy is top priority (going hand-in-hand with remedying functional and qualitative defects as well as floor plans, open space, and lighting).