An external solar shading system
The two-storey drum-shaped building, containing a cafe on the ground floor and a double-height restaurant above, is fully glazed on the south and east to give views over the lochan. The restaurant glazing comprises a Structal curtain wall system fixed to a series of back-to-back 350 x 100mm steel channel columns which run at the perimeter to support the concrete floor slab. It is shaded externally with a system of fixed louvres on the south and east sides. The ground floor is set back from the upper floor, which protects it from solar gain.
Thermal modelling, to reduce solar gain and cooling load, helped to determine the position and type of shading. The louvres are 600mm wide curved blades of perforated aluminium, stiffened at the edges by extruded aluminium tubes. They are hung in rows of three between vertical supports - 600mm wide composite steel/aluminium fins which extend from ground to roof level. Paired back-to-back 380 x 100mm curved steel channels run between the fins to brace them. The aluminium louvres are fixed to the fins at one edge; the other edges are supported by 12mm diameter stainless- steel rods suspended from the channels.
The assembly is tied back to the structure with paired aluminium flats bolted to the curved channels. At first floor level and at roof level the ties support a gridded walkway for glass cleaning and maintenance.
The upper part of the solar shading assembly is restrained by a ring beam. On the north side of the drum the louvre panels are replaced by screens of aluminium mesh; they extend above the roof to screen the plant room.