COMMENDATION – Bishops Square, London

A fully exposed structural steel frame forms a stand-out retail building adjacent to an historic east London market.

FACT FILE
Architects: Foster + Partners, Bond Bryan
Structural engineer: Price & Myers
Steelwork contractor: Elland Steel Structures Ltd
Main contractor: VolkerFitzpatrick
Client: J.P. Morgan

Forming part of the multi-million-pound Bishops Square redevelopment, which has transformed a large area next to east London’s historic Spitalfields Market, a standout steel framed structure has added a further 10 retail and food outlets.

Located on Lamb Street, which runs along the north side of the old market building, the project consists of a two-storey block designed by Foster & Partners. It is a distinctive building, said to be in keeping with the Spitalfields heritage and includes an exposed structural steel frame, coated in dark red iron oxide, infilled by glazing, canopies and partitions to give it a modern, industrial feel.

“Rarely is the steel frame seen in the final condition, the external cladding is positioned to expose the primary frame and connections in all its glory,” explains Elland Steel Structures Commercial Director Jeremy Shorrocks.

“The high decorative finish is achieved through good planning and preparation of the offsite elements, with a final topcoat applied onsite to achieve the uniform finish. The exposed joints were carefully designed to achieve uniformity, while we have some 5,500 bolts in full view.”

To allow the construction of the steel framed retail building, a number of logistical challenges had to be managed, as the structure is situated above an existing basement’s vehicle ramp.

“The basement serves as a car park for an adjacent building and remained ‘live’ throughout our works,” explains VolkerFitzpatrick Project Manager Robert Lindsay.

“Consequently, we had to undertake structural movement monitoring of the steel and concrete basement to allow the construction of the retail building to take place above. Just as importantly, we also had to put a traffic management scheme in place to allow car park users their usual access.”

Above ground, the site is also very confined with much of the available space taken up by the new building’s footprint. One narrow strip of available land was used for deliveries and as a location for the project’s mobile crane.

As well as providing the scheme with its integral aesthetic look, structural steelwork was also chosen for its speed of construction. The material also created a lighter structural frame than many other forms of construction, which was an important consideration as the new building is positioned and founded on an existing car park sub-structure.

The new building is 70m-long × 15m-wide and both floors – the ground level that mostly spans over the ramp and the upper first floor – are compositely formed with metal decking and a concrete topping.

Based around a regular 8m column spacing, one elevation is directly supported on an existing basement wall. However, the main elevation containing the shopfronts has no existing columns or wall beneath the new steel frame’s perimeter line and so a series of trusses have been installed along this façade.

In summary, the judges say one could be forgiven for considering this a relatively modest, straightforward project such is the quality of the design and construction achieved in response to the significant complexities that literally underlie it. The efforts and commitment of the entire team have been amply rewarded in this fine project.