The principal spaces of the centre are on the first fl oor, to give views to the river and nature reserve.
The cast-in situ concrete first-floor and roof slabs project 3m beyond the ground floor, supported on concrete columns.
The stud walls are filled with sheep's wool and lined on the inside with concrete blockwork and on the outside with larch weatherboards.
The centre is isolated and not continuously occupied; to prevent vandalism the two firstfloor entrances are reached by retractable steel drawbridges and all openings are protected with shutters. The sliding shutters to the office and meeting-room windows are shown here.
Each shutter consists of a series of staggered vertical larch boards fixed to a support frame of 100 x 8mm galvanised-steel flats. The inner 200 x 22mm boards are fixed directly to the frame; the outer 150 x 22mm boards are fixed to 63 x 63mm planed timber blocks fixed back to the frame. The sliding gear, fixed to a steel angle at the top of the frame, is housed in a galvanised-steel bracket running above the window; at the base of the shutter a steel channel slots over projecting stub guides at the window jambs. When the shutters are closed, the windows can be opened by the BMS and gaps between the shutter boards allow air to enter the building and cool the concrete slab.