Being a very environmentally sensitive area in the middle of some 500 ancient trees, the site presented architect BDP with some tricky decisions when it came to designing the roof. "None of the trees could be cut down, which is quite a challenge when building a full-sized training centre," says BDP director Chris Harding.
BDP had ensure that the roof of the centre was high enough to accommodate David Seaman's goal kick, yet not so high that it could be seen above the surrounding trees. At the same time, the building had to look sufficiently impressive to reflect its role as England's premier football training centre.
It has taken several years to find the ideal site. "It's situated in a very beautiful area and is intended as a retreat, like a Dominican monastery," says BDP director Tony McGuirk. It will be built on the site of the former home of the Bass brewing family, which is set in rolling Staffordshire parkland.
The aesthetic relationship between the centre and the landscape was vital. The centre will be approached down a long, winding, tree-lined driveway, showing occasional tantalising glimpses of it through the trees. "There is a processional quality to arrival. And the roof a very important part of the centre's identity," explains Harding. "The roof grows from the landscape, rather than an alien form being dropped onto it."
The centre itself offers spectacular views across the parkland from the former lawns of the original house. Because of the site's sensitivity, the centre's outdoor pitches have been designed to thread among the trees.
The shape of the roof, which covers not just the main pitch but adjacent training and fitness areas, was suggested by the rolling landscape, and the arc described by an airborne football. The FA wanted the roof to be at least 21 m high in the middle and 9 m above the corners. The site slopes, so the west side of the roof is almost at ground level and the higher east side terminates in a colonnade, reminiscent of monastic cloisters, overlooking the cedar lawn. This is a natural viewpoint over the surrounding countryside. "Because of the geometry and the sensitive site, we didn't want it to be any higher than 21 m," says Harding. "We drew an arc, but we didn't have any idea how we were going to achieve it."
One possibility was to build an arched roof – but this was ruled out because it would have needed large abutments that would have compromised the aesthetics of the building. "With a shallow arch, you create huge horizontal forces," explains Farahmand Jahanpour, BDP's structural engineering director. "We couldn't have a tie to restrain this as it would intrude into the space. The alternative was huge abutments in front of the building."
The solution was a gridshell roof. "A shell structure resolves the reaction forces within itself. It also minimises the depth of the roof structure, which is only 600 mm," says Jahanpour. Furthermore, a gridshell is curved in two planes so is less prone to buckling than an arch. These advantages mean the roof can be supported on simple columns because they only have to carry the weight of the roof and give lateral restraint.
And a gridshell has another surprising plus. According to Harding, players see kicking a ball up into a roof structure as a challenge. "They lose a lot of balls up in roof structures," he laughs. This shouldn't be a problem with a gridshell roof because they are inherently very simple, without exposed horizontal surfaces. Another factor in the gridshell's favour was that BDP had designed one before – a steel structure at Wimbledon's No 1 court.
BDP has used wood rather than steel for this gridshell because it is more compatible with its environment – and cheaper. "Initially we thought timber would be too expensive. But when we did the costing, it turned out to be cheaper than steel," says Jahanpour.
Because the roof is asymmetrical, every structural roof element has to be a different size, which could be expensive. But here wood is cut to shape using CNC machines controlled directly from BDP's model, which makes manufacturing the roof relatively cheap and straightforward.
The FA has grand hopes for the centre. Harding describes it as the "Oxford and Cambridge of football training". The centre will have special video screens for action replays that can be analysed, as well as medical and media facilities. Until now, the England team has stayed in hotels and trained at local grounds, making it difficult to provide a full range of training facilities. The idea is for the National Football Centre to pull all the different aspects of training such as diet, fitness and science under one roof.
This concentration of resources, which will be at the disposal of all England's teams – from the youth team right up to the top squad – should help bring a definite structure and continuity to the national game. "Integrating all the strands to create excellence," enthuses Harding. The England team will spend a month at the centre, which has good transport links, before a major tournament. The idea is they will be so refreshed and fit, they will be able to take on the world.
The project is on hold at the moment while the FA resolves its current funding problems. All the exterior work, including the outside pitches, is nearly finished; once the financial hitches are sorted out, work can begin on the main buildings.
The centre is scheduled to be completed by 2004. With any luck it will help England win the World Cup in 2006 – just as long as the build programme doesn't go into extra time...