THE CONTRACTOR TAKES A GREATER RISK BECAUSE IT CAN'T ASK FOR TIME EXTENSIONS
Buschow Henley is contracted to design and build a public/private-funded health centre in south London under the new LIFT initiative. Sutherland Lyall talks to project architect Franziska Lindiger about the project and the complex nature of the contract.
The St John's Therapy Centre in Wandsworth is the first of such centres designed by Buschow Henley under the government's LIFT initiative. The acronym stands for NHS Local Improvement Finance Trust initiative and the scheme is intended to build and run public/private-funded GP surgeries and community health buildings. There is a dictionary of public/private-company acronyms and initials lurking in the shadows of this scheme, but the important thing here is that Buschow Henley is the architect under a ú7 million design-and-build-style contract in which it designed the centre and specified in outline - and was then novated to the builder Willmott Dixon.
This is not a standard JCT design/build contract, but one which is devised specifically for the LIFT concept and is much closer to a PFI-related contract.
Buschow Henley, along with Penoyre and Prasad, engineers Whitbybird and Price & Myers, and constructors Willmott Dixon, are partners with the private company Better Health (BH) with which they joined in a three-way pitch for health building work in south-west London. When this building is completed it will be run for 25 years under a lease-plus agreement by a BH facilities managing partner. The building team will have no further interest although it will move on to do more centres in the area for BH. Buschow Henley has already designed the new Waldron Health Centre under the same arrangement - and, say the architects, it looks as though a family of common design traits is emerging.
Although the LIFT company controls the centre's construction and is the body with which the builder has a contract, it has no assets and therefore takes no risk. Project architect Franziska Lindiger says: 'This is not a normal contract.
The contractor takes a greater risk than usual because it can't ask for extensions of time or claim additional costs.' The contract price is loaded to reflect the contractor's risks. A further complication in this case is that Willmott Dixon is a subcontractor to Fund Co, so the building contract is technically a sub-contract, not a main contract.
DECIDING THE SPECIFICATION
The umpire in all this is independent organisation Faber Maunsell, which checks the drawings and specification against what is built and, if everything is satisfactory, will certify that the contract has been met. As for day-to-day inspection, Lindiger says: 'We go on site once a month and go to site meetings, but don't have the obligation to check that everything is built. The employer's agent Davis Langdon is inspecting. We are co-ordinating the design team and delivering the details, the specification and as much co-ordination on site as is required.' The specification on which the builder based its price was developed by Buschow Henley as an outline specification. In it the architect was specific about products which were crucial to the design, such as the decision to use only stainless steel architectural ironmongery. The builder had leeway over other materials where the appearance was of secondary relevance. Naturally, whatever was used had to comply with building regulations and standards so that for sanitaryware - where the contractor chose Armitage Shanks - the crucial thing was that the fittings were compliant with NHS Health Building Notes rather than what they looked like. Radiators, on the other hand, will be by Barlo.
It is an arrangement which has worked so far. Lindiger says: 'Our relationship with the contractor is good and both of us are going ahead following the [principles established in the] outline spec.'
The useful thing about knowing that you are going to design a number of buildings of the same sort is that it is possible to take a little more time in identifying and developing some common design principles. The Buschow Henley design team came up with five. These include the establishment of a clearly defined patient 'journey' through the centre; an emphasis on outside space as a contribution to patient calm; adaptability and flexibility in the planning and structural grid; the use of concrete-frame and flatslab construction; and the use of a polished-sheet cladding material in timber. The last is 'intended to give these sculpted civic buildings a disarming gentleness', something comparable to veneering and marquetry in furniture rather than the currently fashionable weathering timber boarding. This is the city, the architects say, not some sylvan idyll.
At St John's, the plan is arranged around two major courtyards as a kind of double racetrack. The long corridors are mostly single sided so that long stretches are naturally lit by the windows overlooking the courtyards. The two lower floors are for patients, the two upper half floors mostly for staff, and the upper space of the double-height gymnasium is part of the third-level layout. The right-hand half of the ground floor is for two doctors' surgeries, while the other half has its own reception space and caters for people with mental health problems. A flight of stairs leads up to the second level, where patients can consult podiatry specialists, dieticians and a variety of therapists.
Buschow Henley has always been Mac-oriented, so it uses VectorWorks, originally developed on the Mac as MiniCAD.
Lindiger says: 'Since it was bought by Nemetschek it has been improving and we will probably be based on it for a long time.'
The choice of the Parklex 1000 rainscreen cladding was, Lindiger says, to do with 'the dry construction, its 20-year guarantee and the fact that it has a civic presence'. It is a timber-laminated panel with exposed grain on the outside - whose material and scale will integrate into the surroundings, providing a friendlier atmosphere.
'It can be face or secret fixed. We are having it face fixed.' Behind the inside plasterboard there is a 25mm ventilated space, 100mm insulation, a breather membrane and then a Metsec wall system spanning between the floor slabs which allows the panels to oversail the slab edges. The panels are 1.2m wide and are normally 2.4m high, with some at 1.2m and a few at 600mm.
The grain pattern in the 10mm face laminate goes vertically.
Lindiger says: 'It is actually a proper timber grain so there are variations of grain throughout the building.'
ROOFING AND STRUCTURE
Lindiger says: 'Because the flat roofs here are inverted with a membrane over the concrete slab, insulation on top and a ballasting layer of gravel and pebbles, Permanite's asphalt seems to be a reasonable product and, importantly for the LIFT, has a 25-year guarantee. It was recommended by the contractor and is low maintenance.' Internally, the concrete frame allows flexibility of space.
Lindiger says: 'Where possible, the undersides of the concrete slabs are simply exposed so they can form part of the thermal mass [equation]. Where possible, the building is naturally ventilated and is EcoHomes compliant. The concrete also has an acoustic performance and provides fire separation.'
The exceptions to this are where Armstrong demountable ceilings are specified for the corridors to provide cover for ceilingmounted services. Lindiger says: 'We have tried to minimise false ceilings, so they are only found in corridors or in an adjacent strip inside the clinical rooms - the rest is exposed concrete.' Most windows are to be Kawneer. Lindiger says: 'Kawneer was able to do the window sizes we wanted and their price was good. We have used them for the aluminium-fixed windows and Rationel for opening windows, which are aluminium externally and timber inside. There are some really large Glazing Vision walk-on roof lights, and large panels of glass are used on the third floor and in the structure in the right-hand courtyard.
'We have specified Altro non-slip flooring for wet areas, sustainable Freudenberg Noraplan Eco rubber for all the consulting and clinical rooms and corridors, and in the offices we will have carpet.' The latter will be chosen in consultation with the client. The contractor came up with Phillips as the lighting manufacturer but these details will be settled closer to the end of the contract later next year.
Client South-west London LIFT Architect Buschow Henley: Ralph Buschow, Agnieska Glowazcka, Gavin Hale Brown, Jim Corbett, Sidney Denby, Kim Fichter, Alex Flockhart, Simon Henley, Dan Leon, Franziska Lindinger, Craig Linnell, Kate Mallet, Clare Milcoy, Ken Rorrison, Bruno Silvestre, Ben Stagg Main contractor Willmott Dixon Quantity surveyor Davis Langdon Structural engineer Price & Myers Services engineer Whitbybird Building control MLM Building Control Consultant Form of contract Design & build Gross external floor area 3,365m 2Total cost ú 6,743,868.51 Start on site August 2005 Completion September 2006 CAD package used VectorWorks