At 310 meters tall, the iconic Renzo Piano design redefines London’s skyline, with 87-storeys above ground and three below. RBG proposed and developed an alternative construction method (for frame contractor, Byrne Bros) which saved over four months on the programme and significantly reduced risk to the head client, Sellar Properties. The jump-start core method supported the core with plunge columns while the basement and core foundations were simultaneously constructed below. This established tandem work fronts thereby minimizing the risk of delays in basement construction and allowing the superstructure to proceed significantly earlier than the original construction programme had anticipated.

Key technical challenges

RBG redesigned the steel plunge columns enabling complex bracing arrangements and programme hold-points to be removed, hence simplifying excavation and improving health and safety. The ground floor slab was redesigned for significant construction loads and to prop the basement wall whilst maintaining a large void to allow the core to rise.

RBG also checked all permanent works elements for the temporary loads induced by the innovative construction sequence. The construction method further reduced the ground movements, thereby minimising the risk to sensitive network rail facilities adjacent to the site.