Dressed to kill
Egham in Surrey is becoming an attractive out-of-London office location. A case in point is Clarke House, a speculative joint venture between developers Gullane and Quintain and designed by Stiff + Trevillion. Heathrow Airport and the M25 are nearby and there is an efficient rail service from the town to Waterloo and the City.
The architect's first design proposed a 'white-panelled, Meieresque box' but at a final planning meeting the conservation officer insisted on a pitched roof and red brick facades, in keeping with the local vernacular.
Ancient precedents Architect Andy Trevillion agrees that brick is an appropriate choice for Egham, given its many historic associations. Runnymede, where Magna Carta was sealed, is just down the road. Most local housing is red brick and nearby Royal Holloway College offers a resplendent anglicised red brick version of the Chateau de Chambord.
The Clarke House site once housed an abattoir. Clarkes Butchers, facing on to the High Street, was part of the contract and has been converted into a pizzeria. Pig's Lane used to wind between outhouses to the abattoir at the back. By clearing away these outhouses, Stiff+Trevillion made space for an attractive courtyard with fixed seats and newly planted trees. This courtyard forms part of a right of way connecting Egham High Street to the large public car park behind and is used and enjoyed by shoppers on a daily basis.
Modernist approach As committed modernists, the approach of Stiff+Trevillion was to treat the brick as a contemporary 'machined' cladding, in stretcher bond with struck pointing.
Andy Trevillion wanted 'a precise wirecut brick with a sharp arris showing'. He also wanted to emphasise the non-structural function of the cladding: brick as skin.
Since the interior of the concreteframe building had already been designed using a 6m grid (for optimal subdivision of offices), adopting brick for the exterior meant revising drawings in order to reconcile the brick module with the grid and adjusting facade openings so that they matched brick dimensions.
Externally, the route of Pig's Lane and the underlying medieval street pattern is hinted at by a meandering ribbon of Indian Sandstone, which weaves its way across the regularly laid paving slabs of the courtyard. Another reference to the past lies in the choice of brick colour and red-pigmented mortar - 'bright red, like blood', says Trevillion.
Topsy turvy facades The arrangement of the elevations establishes an unconventional vertical hierarchy. The ground floor is fully glazed along the west-facing front and north-facing elevations, with structural concrete columns set forward from the glazing. First floor portrait-format windows are set back half a brick width.
Wider second-storey windows, set back a full brick width, give precedence and transparency to this top floor, in contrast to the gradual reduction of window size towards the top of a conventional, classically proportioned brick building.
There are no expressed sills or lintel dressings; the openings simply punch through the brick skin. The steel lintel to the top-storey windows is painted black and left exposed behind the edge of the cladding. A fillet of powdercoated steel folds over the eaves as a coping and the facade brickwork is restrained at roof level by a visible steel ring beam.
Descriptive glazing Windows are aluminium framed except for those facing the north boundary.
The frames are steel and glazing is fire rated to one hour. The window arrangement here is identical to that on the front elevation but at the rear of the building, instead of detached concrete columns, the structural supporting pier is concealed behind brickwork. Ground floor glazing on the rear wall is broken into two large windows, with mullions positioned to form a middle panel where brick piers would have been used in solid brickwork.
An additional wing, raised on piloti to allow car access to the rear of the pizzeria, extends to the east of the entrance elevation, forming one arm of the right-angled plan. The WCs and staircase are placed in the shadowed angle of the plan, with small horizontal windows indicating the WCs on stair landings.
Variation without frills The few departures from the overall uniformity of the brickwork at Clarke House are used effectively. Screen walls defining the entrance are stack bonded and stand out against the stretcherbonded front facade. A raised flowerbed running around the base of the building is contained by a brick wall capped with brick-on-edge: this has been planted with bushy evergreen shrubs.
Even the brick wall surrounding the car park, with inset railings, has been carefully detailed and finished.
Trevillion has high praise for contractor Barnes and Elliott. 'Design and build, which this job was, has an appalling reputation for quality, ' he says. 'But these days there's a partnership between ourselves and the contractor and they were instrumental throughout in trying to maintain the quality of the project.'