Feature

Tough guys

Concrete proves the right prescription at London's new cancer care centre

Laing O’Rourke’s precast solutions helped to create a vibration-free structure for delicate cancer treatments, writes Pamela Buxton

A predominantly prefabricated approach to structure and cladding enabled the new Cancer Centre at Guy’s Hospital to grow at a rate of a floor every week. But a speedy construction programme, although cost-efficient, wasn’t the only factor behind the choice of precast concrete for both frame and cladding at the £160m building, designed by Rogers Stirk Harbour + Partners (RSH+P) and healthcare specialist Stantec on a tight triangular site near London Bridge station.

According to RSH+P project architect Leonardo Pelleriti, the most crucial criterion was stability, since the building accommodates facilities for radiotherapy and chemotherapy. These are housed in a series of two- or three-storey “villages” stacked within the 14-storey tower. “The structure of the building had to be very stable and rigid to limit vibrations,” explains Pelleriti, adding that any movement could affect the performance of the treatment equipment within.

A concrete column and slab frame was chosen, supplemented by shear walls and cores, with only the basement and main cores cast in situ. The rest of the structure was made at contractor Laing O’Rourke’s Explore factory, with clinical and non-clinical services pre-fitted.

Externally, RSH+P chose unitised concrete cladding in 12m-wide expanses of the facade of both the south-east and south-west walls of the 60m-tall building. “Where there were shear walls, we wanted to express the structural element in the cladding,” says Pelleriti.

These expanses of cladding are enlivened by three circular porthole windows – one large, two small – per floor, designed to line up with various internal elements, such as the end of a corridor.

The architects worked with structural engineer Arup and Laing O’Rourke to develop the panels, with prototypes and mock-ups built at Explore. Each cladding panel is 80mm thick, with dimensions varying to a maximum of 4,200mm in height and 2,750mm in width. Panels are combined with 120mm of insulation which sits between the panels and the 500mm-thick sheer walls.

Inside, patients and staff are in no doubt that this is a concrete building. In public areas such as the main atrium, the lattice slabs and columns are exposed, with the walls and soffit only clad in clinical areas. This helped the design team achieve its aim of creating a welcoming building that felt non-institutional yet was clinically efficient.

“We didn’t want to paint it,” says Pelleriti, who has since co-founded the practice Wimshurst Pelleriti. “We wanted to keep the concrete as natural as possible, like stone.”

PROJECT TEAM

Architects Rogers Stirk Harbour + Parters; Stantex
Structural Engineers Arup
Contractor Laing O'Rourke

Photos: Morley von Sternberg