Stone-Ideas.com 
Stone+tec fair in Nuremberg has an architecture congress (June 19 – 20, 2024) about using natural stone as a load-bearing material
https://www.stone-tec.com/en/stone-tec-congress/
The new building is exceptional in every respect:
* It has a unique location, namely on the edge of the financial district in Geneva, directly on the banks of the Rhone, on the last undeveloped piece of land there;
* Since completion in July 2023, it gives place for ten social housing units and a workshop for the reintegration of people with mental disorders;
* With the type of construction and the selection of building materials, it achieves a minimal ecological footprint and at the same time earthquake resistance;
* The architecture ties it in with the appearance of the adjacent industrial buildings.
It was built in solid construction with small natural stone blocks. Once again, the Geneva office Archiplein has shown that this modular-style architecture allows for a wide range of design options in the façade.
When the Canton of Geneva, as the owner of the exclusive property, handed it over to the Fondation Nicolas Bogueret (FNB) for development, it led to some discussions in the city of money. The foundation is dedicated to providing housing for the disadvantaged. It bears the name of the architect and engineer Nicolas Bogueret (1537-1602), who created several important buildings in the city.
The Archiplein office, headed by Francis Jacquier and Marlène Leroux, won the competition with the concept for a building that is ecologically sound and can be flexibly divided up inside to suit the needs of the residents.
The stairwell, accessible from the side of the building facing away from the river, serves as a stabilizing element in the event of an earthquake. It is built in a U-shape made of limestone blocks. It has post-tensioned steel rods on each face of the U.
The staircase itself is the only reinforced concrete element in the building. It is inserted into the building without being connected to the walls.
Balconies open up from the stairwell, which in turn lead to the apartments.
The stone blocks, which are a maximum of 30 m wide, bear the entire load via the façades and the stairwell. They are placed on top of each other. Mortar keeps them in together in closes the joints.
The walls inside can be moved as desired.
The material for the ceilings is wood (plus 8 cm of concrete mainly for acoustic reasons).
The architects adopted the typical grid façade of old industrial facilities from the former chocolate factory next door and other buildings in the area but adapted it to the demands of today’s living with a reduced ceiling height on the ground floor and enlarged windows above.
The window reveals on the upper floors have a fold that creates a play of shadows depending on the position of the sun.
There are black powder-coated iron bars in front of the windows. The blinds on the river side are hidden behind valances made of folded sheet metal.
As usual, the types of stone were selected according to the requirements: for the external façade, the Pierre de Sireuil limestone and for the stairwell (where the tensioning pressure of the steel rods occurs) the Pierre de Chauvigny limestone. Both were supplied by the French company France Pierre.
Photos: Leo Fabrizio, 11h45: photographie d’architecture
