In 2021 the BIS launched an international architectural competition to propose designs to develop its headquarters site. Participants were asked to come up with a design proposal which would replace the ageing buildings and provide a concept for modern facilities to accommodate the enlargement of global meetings and growth in activities as well as create a campus-like work environment for its staff and visitors.

A total of 11 high-quality designs were contributed to the competition. In December 2022, the BIS announced that the 11-member jury unanimously selected a collaboration by the firms ELEMENTAL (Santiago, Chile) and Nissen Wentzlaff (Basel) Architekten as the winning design.

The jury lauded the ELEMENTAL/Nissen Wentzlaff Architekten design for its innovative and sustainable design. The architects proposed a second tower on the BIS headquarters site which would connect to the existing BIS Tower designed by Martin Burckhardt. The jury felt that the proposed design has potential to enrich the growing skyline of Basel and responds well to planned development in the surrounding neighbourhood. The proposal provides an elegant contrast to the architectural expression of the existing Tower and complements the footprint of Burckhardt's original design. The design was also appreciated for its extensive use of timber and its "forest"-like façade.