Hawkins\Brown performs a feat of precision surgery on a venerable institution, stitching a light-filled atrium and modern HQ between a listed building and a live construction site
The reopening of the Hunterian Museum earlier this summer marked the final piece in Hawkins\Brown’s extensive remodelling of the grade II*-listed Royal College of Surgeons on Lincoln’s Inn Fields in London. The architect describes its approach as “respectfully radical … weaving together the institution’s rich heritage with a modern, flexible environment representative of the college’s vision for the future of surgery”. Historic elements such as the original north facade have been restored and updated while post-war additions have been removed and replaced with a publicly accessible, concrete-framed atrium. This sensitive modernisation – reworking and maximising a limited amount of prestigious central London real estate – has saved an estimated 130kgCO2eq/m2 of embodied carbon, while delivering most of the benefits of a new-build.
If the key to this approach was to establish “a dramatic threshold between old and new”, the challenge was to work out where exactly that threshold should be. “The building has quite a long history of destruction, demolition and rebuilding,” says Andrew Wadeson, associate at Hawkins\Brown. “There was quite a blurred line between what was true heritage and what was replica. Our job was effectively to make that line clearer, and to add another chapter to the building’s story.”
The first Royal College on the site was built in 1813, but all but replaced in 1830 with a new design by Charles Barry. It extended sideways in the late 1800s, taking over two terraced house plots on either side, before a bomb took out a large part of the rear of the building during the Second World War. Rebuilding work in the 1950s included steel-framed structures that sought to replicate the Barry design.
The team undertook a detailed examination of historical records, alongside investigations on site to establish how much of the building was practicable to retain, repair and reuse. A 3D point cloud survey allowed the historic building fabric to be captured and brought into the BIM model. Any structural constraints could then be used to inform the spatial design.
The most dramatic intervention has been the introduction of a new light-filled atrium under a barrel-vaulted glazed roof. This is structurally independent, with the concrete frame cantilevering towards the Barry building’s rear elevation and simply fixing into it via a slotted connection. “The new structure pulls back from the historic brick facade to give it breathing space,” explains Wadeson. The brickwork has been limewashed and the windows have been filled in to form niches to display busts and other objects from the college’s extensive collection.
The concrete frame has been left exposed throughout. Ply formwork was used to create a matt finish, and the mix – which included 30% GGBS – was tested out on two basement levels to make sure the finish and joints were as specified. The detailing is suitably clinical: the beams around the atrium were cast with both downstands and upstands so that they would be flush with the ceiling light fittings and the floor finish above.
The atrium connects to a new rear entrance, which opens the building up to the public and will help to draw people in to the Hunterian – a sometimes gruesome collection of anatomical specimens from the more rudimentary days of 19th-century surgery. This south facade is made from loadbearing precast concrete panels, reducing the need for secondary steel framing and associated maintenance. To lend sufficient stability, the slender beams turn up in an L-shape behind the visible elements. Beams and columns were cast separately – because of the limited space for cranes and storage, units were restricted to a maximum of 10 tonnes.
The aesthetic here references the classical north facade while also being emphatically modern. “The expressed concrete is something that’s obviously new, while also alluding to the historic masonry,” says Wadeson. “We deliberately gave it a slightly different tone – a bit more sandstone, a bit yellower.” The precast also incorporates a fluted motif that echoes the porticoed columns of the Barry entrance, but with sharper, more contemporary lines.
Precast concrete played another important role, Wadeson adds. Part of the complexity of this project derived from its central London site. There was not only a listed building directly in front, but the construction site for Grafton Architects’ Marshall Building for the London School of Economics immediately next door. “There were two live sites, and in terms of both demolition and the new concrete frames, they would accelerate past one another alternately. For any works on the boundary, there were obviously really critical health and safety issues.” The original design was for a hand-laid brick wall, but this would have proved time-consuming, increasing the time spent working at the boundary. “We changed the design to maximize the efficiency of how quickly it could go up, using brick-faced precast panels that we could drop down between the two concrete frames. The speed of that was obviously far, far quicker.” The walls were then sealed and insulated from the inside.
The same approach was taken on the other, eastern elevation. This was a slightly different scenario, as the building on this side was previously owned by the Royal College, but had been sold to the LSE to fund the new works. A new physical boundary had to be created in an extremely tight space – a situation which again lent itself to a precast solution. Unlike the grand Barry facade and the bold, generous new atrium, it is an almost hidden detail – a piece of precision surgery after the more painful processes of extraction, amputation and unsuccessful rehabilitation that marred the building’s past.