The challenge was to find a way, within the constraints of traffic building, to both enhance the internal, often claustrophobic parking environment and make a contribution to the external environment that is characterized by the traditional half-timbered houses of the old town and the idyllic green of the River Echaz. The light open external steel staircase is certainly instrumental in resolving a lot of architectural design problems to the satisfaction of the users. All steel parts are hot-dip galvanized and treated with protective paint. Landings and steps are made of perforated aluminium plates.