Although less was known about the environmental impact of materials when the Inmos factory was built in 1979 than it is today, considerations of environmental economy played an important part in its design. The structure is outside the enclosing walls so that the internal volume - and the energy needed to cool it - is minimised. Services, placed outside for the same reason, can be maintained without disrupting production processes.
In the early 1980s, AHA worked with Ahrends Burton & Koralek on one of the first buildings to be designed consciously to reduce energy use, the WH Smith head office in Swindon. Grouped around courtyards in a collegiate-type plan, the low-rise office buildings have deep basements and concrete-slab floors with coffered ceilings to capitalise on the potential of concrete as fabric energy storage. The Faculty of Law, Cambridge (by Foster and Partners, completed in 1995), took a similar concept - a two-storey-deep basement and an exposed concrete structure containing books and study areas - and enclosed it in a delicate vault of steel and glass. Today, the benefits of concrete as fabric energy storage are widely known; both architects and engineers see it as an opportunity to achieve environmental benefits enhanced with the aesthetic of a clearly exposed structure.
The School of Engineering and Manufacture at Leicester Polytechnic (architect Short Ford Associates), was one of the first buildings designed specifically to demonstrate how the ideals of low cost, energy conservation and the use of natural ventilation and light to minimise pollution can create a fresh and innovative building. To achieve deep, open-plan spaces at ground-floor level, the traditional load-bearing masonry wall structure was reinforced, and the ventilation shafts were supported on cruciform steel struts.
AHA has made further refinements on this theme. Lloyd's Register of Shipping (by Richard Rogers Partnership, 2000) has a composite concrete structure with chilled beams running in the ceiling vaults. The Open University Business School at Milton Keynes, designed with Jestico & Whiles in 2002 to combine low consumption of fossil fuels with high levels of thermal and visual comfort, has concrete floor planks and a cast in situ concrete structure. It has a BREEAM 98 rating of 'Excellent' with nearly 80 per cent, one of the highest assessments ever made. The recently completed library at Brighton with Bennetts Associates has a steel frame supporting cast in situ concrete floors that are designed to exploit fabric energy storage. The low-tech approach to environmental design is exemplified by a small building at Bleddfa, near Ludlow, designed by Tono Mirai to house an art installation. Its sinuously curved walls are formed of rendered straw bales and timber beams support the grass roof.
Grimshaw, a practice known for its cool, Hi-Tech approach, has worked with AHA on a building at the Eden Project, Cornwall, which is designed to maximise the use of renewable resources and minimise the use of energy throughout its lifespan. The structure of the Institute Building is a series of 'hockey-stick' glulam beams on minimal concrete pad foundations. A glazed lantern runs the length of the roof to maximise daylight. Louvres shade the glazed walls from solar gain, and the rooms are naturally ventilated.