Alpine Lodge in Styria
Situated at a height of 2,154 m, this new Alpine shelter has been built to passive-energy standards. At such a high altitude, exposed to strong solar radiation and where there is no infrastructure, the use of active and passive solar technology and the exploitation of rainwater seemed only logical. The location was analysed on the basis of a sun-path diagram, and the compact structure was positioned on a ridge exposed to strong winds so that it would not be buried beneath snow. The heavily insulated and largely closed north, west and east faces – wrapped in a protective layer of snow and ice in winter – minimize thermal losses. The south face, shielded from the wind, opens to the sun in the form of large area solar panels and triple-glazed windows. The internal layout reflects thermal needs. Spaces used by guests are oriented to the south, where the windows absorb solar energy and afford views of the mountain panorama. Access areas and ancillary spaces are located on the north side. The lodge thus operates in a thermally self-sufficient form. Thermal and electrical energy for the building are generated by solar collectors and photovoltaic panels (together with a cogenerating unit fuelled by vegetable oil). A water-storage-tank absorbs thermal energy from the collectors as well as waste heat from the cogenerating unit and from a solid-fuel stove in the kitchen. This energy is used for the hot-water supply and to heat the air intake. The photovoltaic installation provides roughly 65 per cent of the power supply. If the battery charging sinks below 60 per cent, the cogenerating unit is automatically switched on and secondary forms of consumption are turned off until a 70 per cent loading has been reached again. For windproofing purposes, a compact design was chosen, and the windows were sealed internally and externally at the reveals with adhesive strips. Double gratings prevent snow being driven into the ventilated cavity. The top two storeys were constructed with prefabricated timber elements for rapid assembly. Since everything was delivered by helicopter, the weight and dimensions were also limited.