A low-energy apartment building in Graz (Austria) with a head for innovation and a heart for nature is one of the recent projects of Lari & Associates Architects and Engineers, commissioned by the Austrian construction cooperative Neue Heimat. The unusual building site proved a challenging point of departure: Although situated parallel to the Mur river, a nature conservation area, it is separated from the river by a road with considerable traffic. The challenge for the planners was therefore to bridge the gap to the river, but at the same time protect the housing development from traffic noise.
The solution elected is convincing in its elegant simplicity and ecological quality. By positioning a linear building shape perpendicular to the river, the natural environment is visibly and sensibly “drawn into” the building site. From their terraces, the residents have a sweeping view of the river. At the same time, this configuration makes it possible to protect the housing development by means of a combined greenery and noise protection wall, which also improves the micro-climate. The building, for its part, has a purely southern orientation, offering optimum conditions for making good use of solar radiation. This entails, on the one hand, passive solar energy use, as the building is designed to allow warm air to circulate freely. Solar gains are also actively utilized by collectors that provide energy for heating and water heating.
As a matter of course, a compact building shape, good insulation and the prevention of heat leaks are basic conditions for modern quality design. The windows in high-quality insulation glass are equipped with external automatic blinds to prevent overheating of the apartments in summer. The energy-efficient zoning of the oneand two-story apartments rounds off the consistent character of a user-friendly low-energy building.
Due to the project’s low-energy design, heating energy needs are estimated at no more than 35 kWh/m2²a – comparable conventional buildings have heating energy needs twice or three times as high.