The Met Office has just moved all its staff and forecasting equipment to a purpose built facility in balmy Devon – without a second's break in its service. We found out how the project team made a tricky transition into a summer breeze
It never rains but it pours. The Meteorological Office discovered this after it completed the biggest IT facilities relocation ever attempted in Europe. It had to move 1100 staff, two supercomputers weighing two tonnes each, as well as everything else needed to run a 34,000 m2 weather forecasting facility, from Bracknell in Berkshire to a purpose-built building in Exeter in Devon. And the transfer had to be achieved without a single second's break in the Met Office's service.

"The essence of our business is guaranteed output," says Alan Douglas, the Met Office's director of relocation. "Sixty per cent of the world's airlines and many military activities need Met Office data. Our output was needed by both American and British forces in the recent Gulf war; in fact they needed extra services while we were going through the move. We had to be absolutely convinced there wasn't going to be a break in service."

This crucial need for a continuous service shaped the procurement, the design and delivery of the Met Office's new building. The Met Office had run out of space at Bracknell and needed to get into the new building as quickly as possible. Geoff Hunt, project manager for the Stratus consortium, a joint venture between contractors Skanska and Costain and facilities management specialist Group 4 Falck Global Solutions, laughs about it now: "There wasn't too much pressure on us as a contractor, then."

The building's procurement route was unusual, but it helped speed up the programme. Similar to PFI, in that several consortiums bid for the design and construction plus 15-year operation of the facility, the difference was the client paid for the building and the land. "One thing this did for the Met Office was speed the process up, as there was no due diligence process with the banks," says Douglas. The 102-week programme was so demanding that Stratus took the risk of starting the not-inconsiderable enabling works as soon as it reached the preferred bidder stage – before it had actually won the bid in December 2001. The consortium then constructed the building under a design-and-build contract with architect Broadway Malyan and will provide a FM service for 15 years.

Located on the outskirts of Exeter near the M5, the massive facility, now complete apart from some soft landscaping, is almost invisible until you drop into the hollow in which it sits. In plan, the three-storey building is shaped like a hand with five office "fingers" separated by courtyards. Four of them are white render-faced blocks with the architectural focal point provided by the "thumb", a wedge-shaped, glass-clad office with a distinctive overhanging roof.

A central internal street, complete with running stream, bisects the main building east to west. The ground floor contains a restaurant, a library, a gym, a college for meteorologists, showers and meeting rooms. The two upper floors contain large open-plan offices with the critical weather forecasting and IT functions to the north of the street and the administrative offices to the south.

Behind the main building is a large, utilitarian block. This houses the FM department, Met Office workshops and the all-important plant rooms.

A key aspect of the building is that its services must be extremely robust, because the Met Office cannot risk its systems failing for a second. This partly explains why the block at the back is so large – each of the two supercomputer halls needs 1.75 mW to run and cool the computers, and all systems are doubled up in case one fails. The Met Office meets its day-to-day needs from a combined heat and power plant contained in an "energy centre"; the waste heat from this powers absorption chillers and there are back-up generators in case everything else fails.

Douglas is thrilled with the building, despite architectural watchdog CABE expressing disappointment with the design, describing it as "competent business-park architecture". But the Met Office says its unremarkable appearance was a deliberate part of the strategy – higher aspirations would have meant higher risk. "We didn't want too many cutting-edge features that could have gone wrong," says Douglas. "We still wanted a modern design and we are very pleased with the outcome."

The building was designed for fast-track construction and with easily obtainable components – for example, it has a steel frame and most of the cladding is a quick-build steel-stud insulated render system; this also helped the building achieve its BREEAM rating of "excellent".

Construction was phased so that the building could be progressively handed over to the Met Office for gradual occupation. Milestones were set by the client, a significant date being the handing over of the first of two IT halls on 7 December 2001, so the first supercomputer could be installed prior to the staff moving in. Moving the IT equipment at the right time was particularly crucial as the Met Office's weather forecasting is totally dependent on the supercomputers that number-crunch raw data from weather stations from around the world.

"These dates were key for us, as the challenge was constructing the whole building to schedule," says Hunt. "Any delays would have put weeks or months onto our completion dates. Without those dates being met, we couldn't have done it – and it focused the mind."

Sophisticated communications between Bracknell and Exeter were also part of the strategy to meet the milestones and ensure the move went smoothly. A high-speed data and communications link was established between the two sites. "This has been vital as it allows staff to download information from our supercomputer and use it as if they were on site," says Douglas. The link also was used for video conferences between the Met Office in Bracknell and the project team in Exeter, as working closely together was essential to ensure the project ran without hiccups.

Two Japanese NEC supercomputers have been installed to supplement the existing Cray supercomputers, amusingly named Ronnie and Reggie by Met Office staff. Douglas says this won't mean weather forecasts will suddenly become more accurate. "It's an evolutionary process," he says, explaining that a three-day forecast will gain the accuracy of a two-day one.

Interestingly, the Met Office had its building designed to withstand a cataclysmic, once-in-every-200-years flooding event rather than the more usual 100 years. There are five different forms of flood defence between the perimeter of the site and the building.

Perhaps the folks at the Met Office managers know more than they are letting on …