First passive high-rise building in Freiburg, Germany.

The first high-rise building in Germany to be brought into conformity with standards for a passive building during the course of redevelopment is located in the city district of Weingarten-West, in Freiburg. The 16 storey building, built in 1968, is considered to be an environmental demonstration object. The building use 80% less heating energy, which saves nearly 60 tonnes of environmentally harmful CO₂ from being released each year. A new heating system and controlled ventilation was not enough to achieve this incredible energy balance, also important is a well-insulated building envelope. This is why Freiburger Stadtbau GmbH (FSB) decided in favour of the unmatched thermal insulation provided by REHAU GENEO windows.

The goal of achieving improved thermal insulation was set during the initial phase of redevelopment. REHAU GENEO windows were selected, since they not only meet energy efficiency requirements, but also exceed structural and air density requirements by a significant margin. The REHAU GENEO profile has a frame depth of 86 mm and complex multi-chamber technology, which ensures optimal conditions for maximum energy savings. The high-tech material RAU-FIPRO makes the profile especially stable, doing so without the need for steel reinforcements. The steel reinforcements otherwise used to provide stability are simply unnecessary. In this way the best thermal coefficients for REHAU GENEO are achieved, since the cold bridge – which is created by reinforcements – does not exist. Thermal resistance of the wide frame profile: U_f-value from 0.85 W/m²K, depending on the opening U_w-value up to 0.66 W/m²K.