No plant was allowed to penetrate the existing roof fabric, which meant long and tortuous extract ductwork from the kitchen hoods, through the three-foot deep ceiling-void around the circumference of the dome, to get to three of the four turrets that were commandeered for ventilation plant. The extra pressure drops caused by triangular ductwork sections around retained roof trusses inevitably led to greater fan power and more noise attenuation, but after much re-design it all went together.
"The air volumes for the kitchens were around 26 m3/s, and this had to be accommodated in a very small area" said Packer. "A lot of the ductwork also had to be spiral wound and fabricated on site."
Given the nature of the site, John Packer found it difficult to design the services with active sustainable elements. "Solar panels would have been good to use, given the amount of hot water used in the kitchens, but very difficult to do given the preservation criteria," he said.
Nevertheless, the 10-year old boilers were found to have plenty of life left in them, so they were retained and refurbished with new controls, and retained in their original position, but with a new flue. These boilers serve contemporary radiators and the vast Warmafloor underfloor heating system in the dome, which was originally heated by large, cast-iron radiators which ran 24 h/day ("Goodness knows what the energy consumption was," said Packer).
Derby University has turned the dome into the heart of the campus. On a day-to-day basis it serves as an area for dining, for meetings, and for internet surfing, but it is also a major venue for all sorts of events that the University will hold, from fashion shows to concerts to graduation ceremonies. No other University has anything quite like it.
The dome was subject to an extensive programme of restoration. As part of this the client took the opportunity to put in a walk-through services trench under the dome floor to take the piped services to the kitchens, retail outlets and teaching spaces on the two floors behind the colonnade.
English Heritage allowed the use of modern partitioning on the basis that it could easily be removed, but resisted dado trunking or chased-in wall sockets unless the original hospital sockets could be reused. "The dome is effectively a circle within a square," explained the University's Director of Facilities Management, Ian Willgoose. "The real challenge for the design team was how to make the unusual shapes and sizes of perimeter rooms work for 21st century education."
The non-symmetrical and often wedge-shaped rooms around the dome's perimeter have been restructured very successfully. Most fluorescent lighting is of suspended fittings which requires little alteration of the preserved original ceilings and goats hair plaster. Mechanical cooling in the form of dx air conditioning has only been used in the main computer suite of the Learning Centre, and some IT-rich teaching rooms. Most other rooms, retail outlets and dining areas are naturally ventilated.
Repairs were carried out on a like-for-like basis, enhanced by modern techniques, to maintain the maximum amount of historic fabric. While all primary structural elements were repaired, and missing elements restored where there was clear evidence for their original form, restoration based on conjecture was avoided. For example, a new staircase linking the ground and first floor of the colonnade is unashamedly contemporary, as trying to design in the original idiom would probably have been unsuccessful.
Most of the building work was concluded early in 2005, with the fit-out of classrooms and specialist facilities completed by the time the University opened its doors to its 2000+ students in September 2005. With new student accommodation down the road and the potential for expansion, the faculty has increased Buxton's population by around 10% - significant inward investment for a town that has hitherto relied much on seasonal tourist income.