The single-storey building is 160m long and 4m wide; it houses an interpretation centre, a cafe and shop, offices and classrooms. The roof, constructed of cast in situ concrete, is flanked with raised parapets with concrete pavers, acting as a 'promenade' for visitors.
On the south-east side the facade, which butts against the original brick wall of the kitchen garden, is of solid concrete with a glazed clerestory running above the wall. The north-west facade is glazed with a series of clerestory and fixed doubleglazed units in steel frames and the parapet above is supported by delicate cruciform columns formed of four 70 x 70mm angles. The glazing is fixed to a steel transom and slots within the gaps between the angles.
Both clerestories have opening lights to cool the soffit of the concrete slab, which acts as a heat sink.
A series of 4.8m wide storey-height shutters pivot at the eaves; they can be raised by hydraulic arms to a horizontal position to screen occupants from glare. At night in their lowered position they give privacy and security.
The shutters have support frames of 70 x 70mm steel angles which support horizontal rows of 140 x 20mm seasoned oak boards with tapered edges. The boards are fixed to 50 x 38mm vertical green oak battens.
Steel head brackets, welded to the columns, are slotted with stainless steel pins on which the shutter frames pivot. Below the clerestory, 50 x 50mm RSA steel transoms welded to the columns support similar steel brackets with pins on which the hydraulic arms pivot.
In the closed position the hydraulic rams are sheathed in tubes.