Published: 28 September 2015
All images credit Phillip Vile
A project to modernise and renovate Chichester Festival Theatre, a Grade II* listed modernist building in Sussex, has been shortlisted in The Structural Awards 2015. Engineer Ben Scott, from Price & Myers, describes the unique challenges of breathing fresh life into such a remarkable structure.
I have been a structural engineer for eleven years. I was inspired to become a structural engineer by my upbringing in Hong Kong, an ever-changing city where buildings seemed to sprout up daily. This influence, coupled with a love of Lego and building blocks, steered me towards an interest in both physics and engineering.
The Chichester Festival Theatre is an exceptional building. Very few structures before it had achieved the drama of its huge concrete cantilever, and the project pioneered a more collaborative design approach between architects (Powell and Moya) and structural engineer (Charles Weiss). This was a terribly exciting development for engineers, and remains by far the most satisfactory way of working, as it means that the benefits from all professions can be brought to bear on a problem and find the best solution.
That’s not to say that it was an easy project for its designers. Charles Weiss and Partners described the challenges they faced due to a ‘quite exceptional number of chefs cooking this particular broth’ (The Structural Engineer
, September 1963). There were a myriad of last minute design changes - even when the roof was temporarily suspended in the air! With the structure already designed to its physical limits, the structural engineers had to fundamentally alter the way the structure worked while construction was underway.
When we came to the building we therefore not only had to understand the original design, but also the way the structure was altered and finally built. We soon realised that the Theatre was very delicately balanced, and that we could not add further loads to the structure. This was a problem, as the brief called for a new gantry and lighting rig. We had to be really creative to find alternative means of making these heavy additions.
Fortunately that’s a situation where engineers thrive: working things out is what we do, and a good problem, like how to add lots of equipment and weight, without increasing loads on the highly strung roof, was hugely satisfying to resolve: we suggested that a completely new structure should cantilever from the existing proscenium frame, with vertical loads transferred directly into the ground using a pair of existing RC columns.
The new structure, built from steel, cantilevers out above the performance area. This shrewd arrangement of steelwork grants the theatre the freedom to suspend various props and rigging systems from travelling beams above the thrust stage, without putting any additional load on the existing roof.
The theatre has been completely revived by the work our team put into it, despite much of this being virtually invisible to the casual observer. The acoustics and sight lines are better, the audience more comfortable, and we’ve found a way to reach back to the vision of the original designers.
Feedback has been excellent from client, audience and public alike. I’m tremendously proud of the project, and delighted to have helped reveal the original design while making a more modern space for the local community.
Visit The Structural Awards 2015 website to learn more about the awards.