The £11.5 million Synthetic Chemistry Research Laboratories building at the University of Bristol occupies a conspicuous hillside site overlooking the city. Designed by Percy Thomas Partnership with engineer Ove Arup and Partners, it is the product of an exacting and complex brief, executed with a rapidity and precision that invites comparison with the building's scientific function.
The laboratories, which were opened by Sir Richard Sykes, the chairman of Glaxo-Wellcome, are modelled on those developed by the pharmaceutical company at Stevenage; they are key to ensuring that Bristol continues to attract the best chemistry staff and students, and to strengthening the university's relationship with industry. Naturally, organisation and fit-out of the internal spaces was the client's first priority and the architect was given a relatively free hand with the exterior design.
Matching and mixing
Project architect Neil Embleton 'wanted the building to be modern but at the same time to be in touch with its surroundings'.
The site curves westwards from the existing 1960s School of Chemistry and the new building is, in effect, an extension. Its immediate neighbour is the Queen's (Engineering Faculty) Building in brick and Bath stone, set back from a Brandon stone rubble retaining wall. Liver-red Brandon stone is one of Bristol's surprises. It is seen everywhere, particularly in Victorian structures but is no longer quarried; a carefully sourced stone mix produced a convincing substitute - used on the base of the new building to great effect.
The architect wanted a slightly brighter brick than that used on the Queen's Building. Unless bricks are blended consistently by mixing from packs on site as bricklaying proceeds, unsightly banding can occur. To avoid this, a computer-mixed multi-brick was chosen. It was possible to specify the exact shading and ensure consistency between packs. The chosen yellow/brown multi is used as a half-brick skin tied back to a concrete frame and blockwork inner leaf.
The only special-shaped bricks required on the project were pistols cut from standards to fit over stainless steel supports, and cut and stuck doglegs for oblique corners. Pre-mixed, pigmented Designation (iii) mortar was used and the stretcher bonded brickwork has buckethandle joints for neatness and weather resistance.
Designing from the inside out
The awkward site and complex brief dictated the internal lay-out: a clean corridor to the south and a service corridor to the north, with laboratories spanning between.
Ancillary spaces such as offices and computer rooms are at the west end of the plan, and a terminal tower, or 'prow', containing meeting rooms in the north west corner. The 2.6m radius on the prow is the minimum recommended for standard bricks in stretcher bond. On the internal wall of the clean corridor an impressive 2.4m radius has been achieved.
The rough texture of the brick face helps disguise any facetting. Support for the radiused brick cladding is provided by individual brackets fixed to the framed structure at floor levels.
The west-facing elevation's composition of window shapes and sizes is informal and includes portholes set within self-supporting bullseyes built from standard header bricks. Visual unity is established by careful detailing of precast string courses: beneath each course, a single-brick band of blue engineering bricks provides a shadow gap (and also disguises the presence of weep holes). The precast string courses and window dressings have a Bath stone finish, and the lightweight GRP cornice is an identical colour match. A decorative brick band, in a soldier course pattern, separates the two bottom string courses and provides a mounting for light fittings which uplight the brickwork at night. The top floor has been stepped back on this elevation, to lessen its vertical impact and provide space for a roof terrace with splendid views.
The long south elevation is articulated by four projecting towers, each one housing the office of the lecturer serving the adjacent laboratory.
Corresponding towers on the north elevation serve as equipment recesses off the service corridor.
A collegiate interior
The brickwork theme continues inside the building in the exposed walls of the clean corridors, and with carpets, timber doors and purpose-built furniture, achieves an appropriately collegiate atmosphere in the staff offices, in contrast with the necessarily more clinical finishes in the laboratories.
Curtain-wall glazing spans between the towers, giving panoramic views which can be enjoyed from the main work spaces and particularly from the low blue brick window seats. Piers of matching blue bullnose engineering bricks are also used at the entrance to the fourth-floor bridge link into the old building.
The roofline of the new laboratories is probably the most dramatic in Bristol, with its curved plant room roofs - like ski pistes - topped by four massive chimneys clad in spiralling lead sheeting: yet planning permission was obtained without delay or qualification.
Embleton believes that the choice of a sympathetic brick cladding helped to generate this favourable reaction to an eclectic design which sprang from a challenging site and a technologydriven brief.