Restoration of the Elizabeth Tower: pairing tradition and modernity at the Houses of Parliament

What was conceived as a light-touch refurbishment of the Elizabeth Tower (commonly referred to as 'Big Ben') has developed into the most comprehensive restoration in the 160-year history of this iconic Grade I listed building at the Palace of Westminster. During the seven-year life of the project, the rich and complex history of the tower has been slowly revealed, shedding light on the unique structural features of the building, and helping to shape the engineering response to the challenges encountered. Dealing with these has required a wide range of engineering techniques to be applied, from traditional conservation engineering methods to the latest in surveying tools and computer analysis techniques. During the restoration, the roofs – which are constructed wholly of cast iron – were stripped down to the main rafters and every element inspected, repaired and repainted. The clock mechanism was dismantled and sent for refurbishment and the dials restored and reglazed. Weathered stonework was replaced, and external decorations refreshed. A new lift was installed to improve access, alongside upgrade of life-safety systems to 21st century standards.