The Bank for International Settlements (BIS) held an invitation-only competition to renovate and expand its headquarters in Basel, replacing some ageing buildings. The scheme submitted by the Chilean practice of Alejandro Aravena, ELEMENTAL – in collaboration with the Swiss firm Nissen Wentzlaff Studio – was unanimously selected by the 11-member jury, which appreciated its use of wood and of vegetation on the facades.

Some of the other teams that took part in the competition were: Bjarke Ingels Group with Gruner; Boltshauser Architekten; David Chipperfield Architects with Harry Gugger Studio; Dominique Perrault; Foster+Partners with SKREINSTUDIOS; Herzog & de Meuron; HHF Architekten ETH SIA BSA with Tatiana Bilbao; Kengo Kuma with FAB – Forschungs- und Architekturbüro; Mecanoo l with Stähelin Partner Architekten; and SO-IL with KARAMUK KUO Architekten.

In the winning design, a square-plan second tower complements the existing circular one, a 1977 work of the architect Martin Burckhardt. At the level of the plinth, it takes on an organic shape to integrate itself into the premises. The conventional floor plan of towers is inverted: the typical central core disperses along a more porous perimeters. In accordance with the concept of grouping floor levels, every third story is made of concrete, which makes extensive use of structural wood possible. In June 2023 the BIS decided to proceed with the next phase: detailed design development.