Whoever passes the street Brühlgasse in St. Gallen these days, may feel reminded of a utopian film or reading material from the childhood: House No 37 seems to float. Taking a closer look, it quickly transpires that the supposed limbo of the building is secured by a multi-part structure of steel supports and associations.
The initial reference to film or reading material is not surprising. Where new office and commercial space was soon to be commissioned by Senn Resources, the auditorium of the cinema “Corso” was previously located next to other uses. Supports up to 9 m high now bridge the space between the supporting ceiling above the hall and the 2nd basement floor, in which the column loads are transferred via presses and load-distributing stacks of steel profiles to the existing floor slab or new micro pile foundations.
The planning of the supporting structure penetrating the existing structure and of the suitable deconstruction stages posed major challenges for the civil engineers at Lüchinger+Meyer. Parts of the remaining upper floors were still inhabited or used commercially during the deconstruction measures. Additionally the lack inventory records and unreliable geometric preconditions made the complex planning of the construction project more difficult. Frequently conceptual adjustments had to be made due to unexpected findings that only came to light when the building was gutted.
Once the demolition work has been completed, the shell of the new storeys based on the project by Beat Rothen Architektur, accompanied by the successive dismantling of the temporary steel support structure, is to be completed by autumn 2019.