Ein Vergleich von Passiv- und Niedrigenergiegebäuden am Beispiel zweier Wohnhäuser in Österreich

A comparison of passive and low-energy buildings using the example of two apartment blocks in Austria.

The terms "low-energy" and "passive" denote different levels of energy performance of buildings in the context of guidelines and standards in a number of European countries. In the last few years, there have been many discussions as to the benefits and drawbacks of low-energy and passive (and recently, energy-plus) buildings. In this context, the present contribution includes a detailed assessment of apartment units in two building blocks in Vienna, Austria. One of these blocks may be characterized as low-energy, while the other one adheres to the benchmarks for passive buildings. As these blocks have been erected on the same site and at the same time (with many similar construction and layout features), they provide a proper case in point for a comparative performance assessment: the main difference between the two blocks is, setting aside the higher insulation level of the passive building, the ventilation system. Apartments in the passive block use controlled ventilation, whereas the low-energy apartments use mainly window ventilation. The comparative assessment of these buildings was based on measured indoor parameters (indoor air temperature, relative humidity, and CO₂ concentration) in two units of each block over a period of five months. Moreover, the apartments were assessed regarding actual energy use (heating, electricity), embodied energy for construction, CO₂ emissions (both for construction and operation), and construction costs.