The structural engineering of the Leadenhall Building, London

The engineering design was developed by Arup in collaboration with architect Rogers Stirk Harbour + Partners (RSHP). The architecture is guided by the principles of openness, flexibility and legibility, which were the hallmark of early Rogers and Arup projects, most notably the Pompidou Centre in Paris and the Lloyd's building in London. A key aspiration from the outset was for the building to clearly express its engineering systems. Stability is provided by a fully exposed, external braced tube. Temperature loadings had to be considered carefully and led to some unusual design features. Several construction-led innovations were employed, including a solid precast floor system and a core built from volumetric prefabricated steel modules with integrated services. Significant permanent horizontal movements occurring during construction were successfully reversed using an innovative 'active alignment' approach. The multidisciplinary engineering systems, and the collaborative digital methods used to deliver the project, have been described previously. This paper presents a more detailed description of the structural design, with a focus on some of the more unusual engineering solutions.