What does "passive house standard" mean? The passive house standard was defined between 1989 and 1992 by an independent research institute, the Passive House Institute, on the basis of purely scientific and physical findings. It represents a significant improvement on the low-energy house standard and is currently the optimum in energy-efficient construction. The name "passive house" is derived from the passive utilisation of available heat, which is generated by solar radiation and the heat emitted by appliances and occupants. The idea is to utilise passive heat so efficiently and at the same time reduce heat loss to such an extent that conventional heating is no longer required. In this way, passive houses consume 75% less heating energy than conventionally planned new buildings. In the renovation of old buildings, even 90% of the heating energy consumption can be saved. (Residential) buildings must fulfil the following three criteria in order to meet the passive house standard: 1. a comfortable indoor climate is guaranteed without a separate heating system or air conditioning. The annual heating requirement must not exceed 15kWh/(m²a). 2. the comfort criteria must be met in both summer and winter. 3. the specific primary energy consumption for all household applications, such as heating, hot water and household electricity, must not exceed 120kWh/(m²a). The passive house standard combines a high level of comfort and cosiness with minimal energy costs and a careful approach to our environment. Whether residential or office building, a passive house can be designed in all construction methods (solid, lightweight or mixed construction) and with all materials and according to taste and architectural wishes. Taking the aforementioned criteria into account, the passive house offers every building owner and planner a great deal of design freedom.