The principles behind Principal Tower – a new residential tower in central London

This paper describes how the 50-storey residential Principal Tower was designed and constructed on a site in the London Borough of Hackney close to the City of London. Design and construction were heavily influenced by the presence of railway infrastructure. However, the design strategy was fundamentally different to the approach used by the designers of nearby buildings, where engineering to accommodate the railway is expressed in the architecture. Visually, at Principal Tower, it is as though the subterranean railway does not exist.