An innovative façade retention system designed by Skanska is preserving a piece of Regent Street heritage. According to client project manager Buro Four, the clever design was a major factor in Skanska being awarded the contract.
The system supports the original 1920 Grade II listed stonework façade of Plaza Cinema on the corner of Regent Street and Jermyn Street while Skanska transforms the interior into modern retail and commercial accommodation above a new two-storey cinema complex.
Skanska UK Building’s head of engineering, Kumar Balakumar, explained, ”Our challenge was to develop a secure, robust propping system that didn’t take up space on the busy public pavement outside the building or clash with demolition work and construction of the new permanent steel frame.“
The solution was a single steel tower underneath the building’s distinctive retained dome, with radiating beams retaining the curved façade beneath the dome. Steel trusses of 22 and 30 metres span from the tower to each wall, with minimal encroachment on the building’s exterior and no impact on the façade itself.
Barry Cook from Buro Four, project manager for the developer Chelsfield, said, ”By using one tower for both the dome and façade, Skanska’s solution was technically ahead of the other contractors during tender stage”
Kumar said, “Our design creates several benefits. By using one support tower instead of separate towers for each section, it requires less steel, producing a major cost saving as well as simplifying the installation.
“The coordination of the retaining system through one tower makes it easier to construct the permanent steel frame around it – almost like fitting a glove on a hand! Overall, it is a major benefit on the programme timescale.”
Prior to the propping system being erected, Skanska carried out extensive surveys of the building to establish the location of existing lattice trusses and plate girders to ensure that the developed scheme fitted into the existing building without destroying its structural integrity.
The entire façade retention scheme was developed, designed, detailed, coordinated and supervised by Skanska UK Building’s in-house engineering department.