Denton Corker Marshall

20 Cannon Street is an existing six storey office building located in a prominent position in the City of London, overlooking St Paul’s Cathedral. The original building was constructed in 1959 and had been fully refurbished in the 1980s. Allied London’s brief for the project was to regenerate the existing property to give it the look and feel of a new build development.

The design incorporated a comprehensive strip back to the existing structural frame and a complete re-clad. The new facade is designed with triple glazed unitised panels that span across the width of each structural bay and over the full floor to floor height. This not only increases daylight into the office areas but also takes full advantage of the spectacular views over St Paul’s.

The cladding panels in the southern elevation include an interstitial copper mesh which acts as a shading device. The simple glazed form of the completed building, with its pared-back detailing, achieves the client aspiration of creating the impression of a newly constructed office development on this key city site.



  • Shortlisted for AJ Retrofit Awards 2012
  • Longlisted for BCO Awards 2013
Allied London
London, UK