Sutherland Lyall puts C F Møller’s Darwin Centre at the Natural History Museum under the microscope
Despite being relatively little known in the UK, C F Møller is Scandinavia’s oldest and biggest practice, with 314 staff in six offices around Europe. The firm currently has projects in 10 countries and 10 major museums on its completed projects list. So when London’s Natural History Museum commissioned it in 2001 to design the £78 million second-phase of the Darwin Centre (a research and visitor facility opening in October 2009), it was not exactly taking a chance on an inexperienced practice.
C F Møller has completed its work but the fit-out will take almost a year while exhibition designers and scientists move in. But the building already makes a striking addition to the area behind Alfred Waterhouse’s Natural History Museum in South Kensington, London.
It’s a vast, mysterious ovoid, wrapped by an orthogonal glass skin with translucent ETFE roof. Technically, it is a link between the old building and the existing first stage of the Darwin Centre. The 65m-long cocoon (as the ovoid is now known) contains five levels of rolling storage for specimens and three upper levels for exhibition, storage and laboratory space. A solid block at the north end has laboratories, offices and a lecture theatre.
The cocoon is finished in polished plaster, which is criss-crossed by thin lines that look like fine string but actually mark the limits of a day’s plastering. The eight-storey glass facade has none of the internal strutting you might expect from such a long vertical span, and individual glass panels spread over the 3m column spacing with very thin transoms in between. Overhead, the whole space is roofed with 3m-wide ETFE sausages divided longitudinally into two cells that lie between the steel beams continuing the spacing of the facade mullions. It is very Scandinavian, in the sense that much has been made out of a limited palette of materials.
It’s a vast, mysterious ovoid, wrapped by an orthogonal glass skin
C F Møller partner Anna Maria Indrio says: ‘It was a complex brief, as it was not only a museum, but archive and laboratories as well. It was also complicated because there were a lot of people changes. We were probably the only ones to last all the way through the project.’
C F Møller has to be flexible when it works in other countries. Indrio says: ‘We have to recognise that things are done differently in England.’ She sees the architect as a more traditional figure in the business of construction: ‘We do things a little bit more simply in Denmark.’ In other words, specialist expertise such as fire strategy, cost and disabled access are all to be found in the practice. Indrio adds: ‘Architecture is not done by dividing itself into pieces. Its part of our strategy that we all work together as one.’
With that in mind, C F Møller decided against collaborating with a local practice. Indrio says: ‘We do a lot of work abroad and part of the practice strategy is that we want to be part of the local culture, like an English firm. So by the time stage C had been finished in the Copenhagen office, we opened an office in London with London architects.’ Indrio, as design leader, had complete control over the whole process. ‘So I didn’t have to explain to another architectural practice what I wanted.’ Thereafter, Indrio was in London at least once a week. She says: ‘We had already made the main decisions in Denmark – such as the face of the cocoon. But in London, [lead architect] Andy Nicholls was fantastic because he knows about all the necessary legislation.’
The contract is an NEC3 contract suggested by cost consultant Turner and Townsend. Nicholls explains that this was based on the Egan principles of collaboration rather than conflict. ‘We are familiar with JCT contracts, and with different contractual methods such as management contracting. As far as we are concerned, with any contract the relationships are more important than the contract form.’
To cope with the differences between the NEC and JCT approach, Nicholls says that C F Møller ‘had a lot of training sessions from the people who wrote it. NEC3 is supposed to give you up-to-the-minute cost information within two or three weeks. So any cost variations are worked out and we get no nasty surprises.’
But it didn’t quite work out that way. Nicholls says: ‘For commercial reasons a lot of the core provisions of this contract were overridden.’ One of these reasons was pressure from the lowest tenderer and from funding timescales. Nicholls says: ‘If you amend wording which has been worked on for years, then you alter it at your peril.’
HATCHING THE COCOON
Nicholls says: ‘The cocoon was a bit of an unknown as not many firms specialise in this scale – we had to trawl through companies who did tunneling work, piling and wall-lining, but principal subcontractor Shotcrete was up for the challenge and got stuck in.’
The 300mm-thick shell was sprayed starting at the bottom and more or less following the sequence of slab-laying. The re-bars at the edge of each floorslab were bent up and down and wired into the shell reinforcement. The concrete was sprayed in several layers through the reinforcing bars from the outside on to a fine 3mm mesh, so that not much spray got through to the interior of what were to be specimen stacks.
A render coat was later applied to neaten the inner shell. Nicholls says: ‘It was a filthy business: full breathing gear; lots of spatter and debris; surplus concrete remixed and re-applied. They used a lightweight concrete with a lot of fuel-ash in it. Because there were a series of layers, and tolerances were 25mm, they employed a specialist 3D surveyor. He was a really good guy who would just turn up with his laser.
‘It was very exciting watching the boat-shaped floor plan being constructed. You expected it to be quite sophisticated but it was just blokes bending big bits of plywood around. But we were impressed with the concrete work.’
Armourcoat was chosen to provide surface plastering. ‘Armourcoat really embraced the challenge of the cocoon’s external surface. They were keen to work with us and to work out the methodology of the cocoon’s smoothness as they hadn’t worked on anything of that scale before. But they were very collaborative and genuinely interested in doing beautiful things with the project. We had thought of using ordinary painted plaster, but it had rates comparative to polished plaster, and as the design developed we did away with the movement joints – except when one day’s work butted-up against another.’
Permasteelisa, an Italian firm, handled the cladding. Nicholls says: ‘We worked with the Italian design team, who came over, and they gave us a lot of options on such things as glass [ply] build-ups, fritting and detailing. Obviously we had to go with the product they were prepared to warrant us, but we got very high quality for the cost we paid.’
‘When developing the internal finishes, we debated the most effective and cost-effective material – we must have gone through every known marble,’ says Nicholls. In the end, Portland limestone was used. ‘I’ve worked with [supplier] Albion Stone before and they were keen to help.’
Client Natural History Museum
Architect C F Møller Architects
Main contractor HBG Construction
Quantity surveyor Turner and Townsend
Structural engineer Arup
Services engineer Fulcrum Consulting
Fire engineer Buro Happold Fedra
Acoustic engineer Sandy Brown Associates
Access consultant David Bonnett Associates
Form of contract NEC3
Gross external floor area 16,000m2
Cost £78 million
Start on site June 2006
Completion on site August 2008