A formal number
Take a good look at Brindleyplace. There is probably no better advertisement on a single UK site for the variety and vigour of brickwork than this resounding success story located in the heart of Birmingham. Set around an attractively landscaped square with cafes and fountains, the scheme comprises a group of speculative, brick-clad office buildings which are harmonious both in terms of massing and materials. Yet the style of each could not contrast more with its neighbours, ranging from the scholarly Graeco-Roman classicism of Porphyrios Associates to the uncompromising modernism of Stanton Williams.
Brindleyplace is the product of two important generators; the enlightened policies of Birmingham City Council and the vision shown by developer Argent. Consequently, a former industrial wasteland has been transformed into a vibrant urban sector, where the spaces between the buildings are as important as the buildings themselves.
The latest addition to Brindleyplace is Number Six, a £12.3 million, orangered brick speculative office block and the second building in the square to have been designed by Allies and Morrison. Its classical symmetry and semi-industrial feel are imparted by an insistent rhythm of brick piers and gunmetal grey fenestration. Such rigid formalism marks out Number Six as a place of work and the only building in the development to eschew the asymmetric disciplines of the masterplan. This is generated from its central location within Brindleyplace and the only building to face two squares, the main square at the front and the smaller, less formal Oozells Square to the rear.
The architect has exploited this duality by making the elevations to the squares calm and open, while those on the side are - due to their subordinate role - more solid and closed. Yet despite this duality, the building's four elevations are unified by a tripartite sub-division which can also be seen on neighbouring Number Two: a doublestorey base of brick piers extending around the building and forming a colonnade on the front elevation; a middle, four-storey section with brick piers expressing the office grid; and on top, a two-storey glazed loggia that provides an interesting silhouette.
The eight-storey building comprises 8,500m 2of office space arranged over seven floors. The ground floor is mostly taken up by the reception area and a 420m 2restaurant facing Oozells Square at the rear. A relatively compact atrium which begins at first-floor level funnels daylight into the core of the office plates and rises to form the base of an open courtyard around which the top two storeys are arranged. Because of its compact size, this relatively short vertical rise of atrium achieves comfortable proportions and thus avoids comparisons with a utilitarian lightwell.
A two-storey basement substructure of in situ reinforced concrete forms the foundation for the building's steel frame and composite floor construction. Cladding is cavity walling with external orange-red facing brick and internal concrete block leaf, separated by a cavity partially filled with insulation. The original intention was to wrap a conventional half-brick external skin around the entire structure, supported at floor levels on the building's steel frame. However, the convoluted brickwork on the side elevations would have necessitated complex slab edge details and special shaped mild steel support angles.
The solution adopted was the more economical 'off-frame cladding' arrangement that obviates the need for a steel support system; a selfsupporting, one brick (215mm) thick, Flemish bond external leaf was built from the foundation level for the full height of the brickwork. It is reduced to half-brick where necessary, mostly for the rebated vertical slots below window sills. A constant-width cavity has been maintained behind the vertically continuous wall which, for stability, is tied back to the structure by sliding anchor ties. The large area of brickwork on the side elevations necessitated vertical movement joints at alternate piers to accommodate thermal and moisture movement.
A different construction on the front and rear elevations avoids the need for vertical movement joints as brickwork is mostly confined to halfbrick storey-height 'piers' between the windows. Here, the construction is cavity walling with a half-brick external leaf. Running round the building at every storey height are continuous string courses of reconstituted stone which are built into the brickwork and tied back to floor slabs with sliding anchors.
Overall, the crisp detailing on Number Six, allied with its strict formal composition, introduces a dynamic rhythm to a site where informality is the order of the day. The design and build procurement route chosen and the use of new working methods, partnering and prefabrication, have resulted in a very economical building costing only £1,073/m 2including fit-out - about 15 per cent less than that normally required for a similar building in Birmingham city centre. Yet the important point about Brindleyplace is that the focus rests not on any individual building, but on the overall concept. All parts are subservient to the whole, a concept which has proved to be a winner for the developer, the city council and for Birmingham itself.
Argent Concept architect Allies and Morrison Production architect Weedon Partnership Structural engineer Curtins Consulting Engineers Design and build contractor Carillion Photography Peter Cook/VIEW