passivhuse

Passivhuse is the Danish term for passive houses, a building standard developed to dramatically reduce a building’s energy consumption while maintaining comfort. Originating in the German Passivhaus movement in the 1990s, the standard emphasizes extreme energy efficiency through a tightly sealed, well insulated envelope, high-performance windows, and mechanical ventilation with heat recovery.

Core principles include very low heating demand, controlled ventilation, and minimized thermal bridging. Buildings typically achieve a heating demand of no more than 15 kWh per square meter of net living area per year, and a total primary energy use not exceeding 120 kWh/m2 per year. Airtightness is pursued to a level around n50 0.6 h-1 or better, depending on the climate. A high level of insulation, solar gains, and efficient shading contribute to comfortable temperatures with minimal seasonal variance.

Implementation and certification are usually guided by the Passive House Institute (PHI) in Germany, and many projects are certified as Passive House (PHI Standard). EnerPHit is the retrofit variant for existing buildings, while variants like Passive House Plus and Premium reflect additional requirements such as on-site renewables.

Benefits of passivhuse include reduced energy bills, improved thermal comfort, and better indoor air quality due to continuous mechanical ventilation with heat recovery. Costs are typically higher upfront, reflecting the specialized design and construction, but proponents point to lower operating costs over the life of the building. The standard has been widely adopted in Europe, including Denmark and other Nordic countries.