One City Road is a landmark office development by Marshall CDP, located at the southern gateway to Manchester city centre within the First Street regeneration zone, forming part of a wider initiative to deliver over 1 million sq ft of new commercial space, the scheme aims to provide a sustainable, high-quality workspace.

Building 1 is a 15-storey, triangular-plan office building supported by a steel frame with precast concrete cladding and a reinforced concrete core. The design incorporates long-span composite floor slabs, a perimeter column grid, and transfer beams at setback floors. The structure is laterally stabilized by 300mm RC core walls, and the design has been developed with future adaptability and fire resilience in mind.

Key Challenges

A key structural design challenge arose from the complex geometry and cladding alignment requirements. On the east elevation, the curtain wall sets back at the first two floors, necessitating two rows of columns and short transfer beams to support the 12 floors above. Additionally, the building plan rotates from the 10th floor, resulting in a shift in the column grid and the need for further transfer beams at this level to support four upper floors. These transfer conditions introduce uneven load paths and lead to variable deflections in the perimeter columns which in turn affect the precast cladding panels mounted via stubs. Accurately predicting and coordinating these deflections throughout various construction stages is critical to ensuring correct alignment of vertical movement joints and maintaining façade integrity.