The primary structure is a flat slab design with lateral stability provided by reinforced concrete cores. To provide more open plan space, a lightweight steel solution was adopted for the penthouse which also supports a ‘brown’ roof. The change in grid for basement car parking is provided by a grillage of transfer beams, with all gravity loads supported by piles. PJCE also carried out the design of the load-bearing masonry façade. Running through the site was an 1800 diameter main route sewer, which required diverting to allow the full construction of the basement. The diversion was detailed and agreed by PJCE with Thames Water and subsequently installed utilising pipe- jacking technique.