The exterior of the Michael Young Building at the Open University Business School shows its environmental credentials
The Open University Business School is the largest in Europe. Thirty thousand students - from the UK and at least 40 other countries - sign up each year for its distancelearning courses. The 350 academic and administrative staff who run the courses previously occupied temporary offices scattered around the Milton Keynes campus.
Now they are housed in the purpose-built Michael Young Building, designed by Jestico + Whiles and named after the radical thinker and inspiration of the Open University who died last year.
The building occupies a pleasant site overlooking fields and countryside on the Walton Hall campus at Milton Keynes. In the spirit of its namesake, it is radical in terms of planning, environmental approach and construction. This is evident at first glance; the main entrance is a ramp that passes between walls of white and cobaltblue render, with a plinth of weathering steel Cor-Ten cladding.
Although most of the staff are academics, the Business School is not a conventional university faculty - for a start there are no resident students. Together with the architect, the staff were keen to explore new ways of working. 'We wanted to challenge the conventional notion of academics and their staff confined to cellular offices, ' explains project architect Jude Harris. Client and architect analysed different 'work settings' and evolved a concept: to provide an environment that would act as a catalyst, encouraging interaction among staff in an informal, 'serendipitous' manner, such as impromptu meetings in corridors and break-out spaces.
The building has been designed to be as flexible as possible, so that a range of working configurations (cellular, group and open plan) can be created wherever they may be needed. It is three storeys high and Hshaped in plan. The central core contains communal areas and links the four 30m x 12m wings, which house workspaces. The central core is a place for informal interaction - all staff enter, circulate and leave through it - and it houses a cafe and a range of more formal meeting rooms. The column-free wings are designed on a 2,700mm planning grid, which allows partitions to be installed to create cellular offices or group working areas.
The building has been designed to achieve the sustainable development requirements of the brief: low consumption of fossil fuels and electricity, combined with high levels of thermal and visual comfort.
The workspaces are naturally ventilated, with individual control, and face east/west to maximise views of the landscape and passive solar gain, while limiting unwanted solar glare.
Assessed by the BREEAM 98 method for offices, the building was rated 'excellent' with nearly 80 per cent, one of the highest assessments ever made.
The end walls of the workspace wings are glazed and clad with a rainscreen of untreated oak slats. The side walls are formed of blockwork piers used as permanent formwork for cast in situ concrete infill, and clad on upper floors with white insulated acrylic render. This allowed the windows, which are set between the piers, to be a relatively generous 1,800mm wide. A Termodeck floorplank system rests on the piers.
To give the building a visual solidity at its base, the ground floor walls are clad with weathering steel Cor-Ten panels. The piers and window spandrels are clad with panels running alternately along the facade, forming a strong articulated plinth-like facade.
The panels are an open rainscreen, standing proud of the rendered reveals of the windows to acknowledge their independence. They form an intriguing contrast to the render, particularly at the main entrance ramp, where the window reveals are rendered in a vivid cobalt blue.
To prevent rainwater run-off from the panels staining the ground, a margin of local ironstone pebbles is set below it.
The external appearance of the building - its Cor-Ten panels, untreated oak cladding and render - provides appropriate outward signs of its environmental credentials and radical approach to layout and design.
ARCHITECT Jestico + Whiles: Heinz Richardson, Jude Harris
CLADDING CONSULTANT Montrésor Partnership
STRUCTURAL ENGINEER Anthony Hunt Associates
SERVICES ENGINEER Halcrow
QUANTITY SURVEYOR Currie & Brown
LANDSCAPE ARCHITECT J & L Gibbons
CLIENT Open University Estates Division
PROJECT MANAGER Malcolm Reading & Associates
CONTRACTOR John Sisk & Sons
SUBCONTRACTOR TR Freeman
Open rainscreen of weathering steel panels
The three-storey building has four 30m x 12m wings of precast floor slabs, supported on reinforced blockwork piers set between window openings.
The external walls of the upper two floors are clad with white insulated acrylic render.
The external walls at groundfloor level are clad with a series of 4mm-thick weathering steel Cor-Ten panels. The piers are clad with single panels, 930mm wide x 2,603mm high and the window spandrels are clad with single panels, 1,637mm wide x 840mm high. The panels act as an open rainscreen. They are flanked by aluminium window sills and jambs clad with insulated acrylic render.
A series of cladding support brackets of heavy duty hot-dip galvanised steel was bolted to the blockwork piers and spandrels.
Each bracket was specially pressed, profiled and fitted with drain holes to encourage rainwater to run off away from the cladding panel. The brackets were sealed to the blockwork and both were waterproofed with a liquid bituminous membrane. A 70mm layer of aluminium foilfaced insulation was then fixed to the blockwork, with the brackets projecting through it.
The upstand leg of each bracket was wrapped with a separating membrane to prevent panel and bracket touching and to cushion the panel, preventing it from rattling. The membrane overlaps the bracket by 10mm on each side to direct rainwater beyond its edges.
The backs of the Cor-Ten panels were pre-welded with 4mm-thick Cor-Ten 'hooks' - flattened Z-shaped sections - to correspond with bracket positions. Pier panels have six hooks. They were lifted manually into position and 'hooked' on to the brackets.
Lightning protection is achieved by using Cor-Ten connecting bars fixed to studs pre-welded to the backs of adjacent panels.