Pick Everard’s design for the British Geological Survey busts BREEAM’s ‘Excellent’ standard using natural materials and the UK’s first timber-supported TermoDeck system, writes Sutherland Lyall
Leicester-based practice Pick Everard won the pitch for the roles of architect and lead consultant for the new offices of the British Geological Survey at Keyworth, Nottinghamshire, following its feasibility study. The results suggested that six of the existing offices on the site, once a residential teacher-training centre, should be demolished and replaced by a single 3,000m² building.
The new William Smith Building, as it is known, takes the form of two three-storey rectilinear wings arranged in an ‘L’ formation with a quarter hemisphere atrium at the knuckle, clad in curving ETFE pillows. The atrium encloses curving stairs leading from open balconies at each floor level down to ground level. The two wings - open plan with a few cellular offices - have stairs and cleaning facilities in a narrow block across each end, with lavatories and kitchens at the inside corner of the north block.
The contract called for a successful post-construction BREEAM review. The current score is 73.7 per cent - better than Excellent. Green aspirations meant measures such as sheep’s wool insulation, rainwater harvesting, low-energy TermoDeck HVAC and visibly natural and weathering materials such as terracotta, copper, timber and, this being a major centre for the study of geology, stone.
The unusual feature of this building is its deployment of a timber frame to support concrete floor panels. Pick Everard’s Chris Gilbert says: ‘We used a glulam timber frame. The floor panels supplier, TermoDeck, was nervous about laying them on timber but the structural engineer, Ramboll Whitbybird, pointed out that, although it hadn’t been done before in the UK, it wasn’t structurally any different from a steel or concrete frame.’
We had to maintain a good thermal performance in the glazed structure
The frame deploys storey-height solid columns joined by flitch plates located just above floor level. Columns are arranged as a three-row grid with TermoDeck panels spanning half the width of each wing. Instead of having a braced framework at the ends of the wings, the walls are 120mm-thick, solid laminated timber, building-height panels. On the outer face are timber studs with Second Nature sheep’s wool insulation and then the rainscreen of timber and terracotta.
TermoDeck is a fan-assisted, energy-efficient HVAC system that makes use of massive thermal panels. These have a number of hollow cores that can be connected together, blocked off, accessed from above and below, and can carry cabling.
The temperature of the panels is controlled by the air passing through them. At Keyworth, three of the five cores are used to move air around from supply pipes running either side of the central row of columns. Air is fed from openings in the upper face of the TermoDeck into the plenum formed by a raised floor system. After painting, the undersides of the panels read as plasterboard.
Gilbert says: ‘We had to maintain a good thermal performance in the atrium and looked at the effect of glazed structures. We talked with Ramboll Whitbybird, which had experience of using ETFE. ‘We contacted Vector Special Projects, which had done the Eden Project and the swimming pool for the Beijing Olympics. The pillows [which run in full-height segments] have been developed by the main contractor with Vector. Each pillow fits into extruded aluminium strips, with the air pipes concealed at their junction with the natural stone band of panels around the base of the atrium. Installing the complex geometry of the pillows required three or so adjustments. The contractor had a three-dimensional survey made of the frame so that Vector could adjust its system.’
Naturally, there was a lot of on-site expertise available for selecting stone. The gabions used for the building’s plinth are made with Mountsorrel granite from Lafarge Aggregates, in cages manufactured by Wolverhampton-based Hy-Ten Gabion Solutions. These are 300mm wide and the face dimension of the cages is such that there are full panels and no cutting at corners or ends.
Gilbert says: ‘The wire-work was arranged in a more architectural way and was a lot more robust than highway gabions. Because of their 3m height there was a need for additional reinforcing at their backs. The cages were filled by the contractor’s skilled stonemason rather than by a general labourer, so the gabions are effectively drystone walls.’
Inside the atrium, the flooring comprises large panels of Caithness slate from the eponymously named Caithness Slate. The inner face is made up of panels of stone from around the UK, selected with the help of the BGS architectural advisor.
This was an NEC3 design and build contract with the full design team retained in an advisory role by the client after the appointment of the contractor, SOL Construction, with Turner and Townsend as project manager. There was no novation to the builder and SOL Construction brought in its own design team of architect and engineers to take the scheme to stage E on the basis of Pick Everard’s detailed drawings and performance specification.
Gilbert explains: ‘NEC3 seems much more communication-focused than a JCT form, where you tend to put the document in a drawer unless there is a dispute. With NEC you have the documents open on your desks on a weekly basis.’ This is because NEC has such features as an early warning notification of possible problems and activity schedules, against which monthly valuations are made.
Title of project William Smith Building
Client Natural Environment Research Council/British Geological Survey
Architect Pick Everard
Main contractor SOL Construction
Quantity surveyor Turner and Townsend
Structural engineer Ramboll Whitbybird
Services engineer Zisman Bowyer and Partners
Total cost £6.2 million
Gross external floor area1,180m²
Form of contract NEC3
Start on site September 2007
Completion on site Phase 1 March 2009