Scouts' Hostel in Ludesch

The St Martin’s scouts’ hostel in Ludesch belongs to a tradition of innovative timber architecture in Vorarlberg, Austria. The building, with its clear, cubic formal language, is set at the edge of the site parallel to the road, which helps to create a well-defined entrance situation. At the same time, the structure separates the wooded area to the rear – an untouched playground for the scouts – from the road. With this project, the planners implemented an experiment in which they sought to build economically, in a radically simple form and with a sensible energy concept. Unlike conventional passive-energy structures, the building functions without insulated outer walls and a controlled ventilation system. Extensive glazing to the north face ensures good visual contact with the verdant outdoor space as well as ideal daylighting. Conversely, minimal south-facing window areas help to avoid overheating through insolation. The two canopy roofs – to north and south – provide ample sunshading. The overall thermal balance is regulated solely by the yield from the solar collectors along the south face and by the dynamic storage potential of the solid structural elements. The non-insulated concrete ground slab functions, in conjunction with the earth, as a seasonal storage unit for energy. In contrast to conventional solar accumulators, the system has the advantage of an unlimited capacity. As a result, solar energy can be stored and exploited to 100 per cent. Up to now, the energy concept for the building has proved its efficiency during the heating period: the dynamic behaviour and the permeability of the solid timber elements in transporting moisture ensure a pleasant cooling effect in summer. Despite the lack of thermal insulation between the solar collectors and the timber, no overheating of the latter has been recorded. Solar energy amounting to 12,000 kWh for the period between June 2004 and January 2005 has guaranteed a minimum indoor temperature of 16°. As a result, the actual energy consumption factor for the scouts’ hostel amounts to only a ?th of the index based on conventional methods of calculation.