New Street Square’s major City of London development comprises five commercial buildings ranging in height from five to 17 floors. They are all positioned over a single basement. Walsh was responsible for the detailed design of the superstructure. All the blocks utilise a long span post-tensioned flat slab solution. This minimises structural depth and reduces deflections. Our engineers provided detailed stability analyses of each high rise block. Amongst other outputs, this allowed for a 3D sequentially loaded model that calculated expected lean of the building cores due to eccentric loading.