A glazed 'street' supported by branched columns
The space between two '60s two- and three-storey teaching blocks has been enclosed with an 8m high roof and a glazed wall to form a 'street',7m wide and 60m long. It links the old buildings with new ones and creates an informal space for children to meet as well as a more structured space for exhibitions or displays.
The monopitch roof rises 8m to overlap the eaves of a three-storey block; a row of aluminium louvres set below the ridge ventilates the street by stack effect.
The glazed roof is supported by five branched steel column 'trees', each with a 323.9mm diameter x 25mm CHS 'trunk' with a splayed oval top plate. The branches, 114.3mm diameter CHS struts, are fixed to the trunk with pin joint connections at irregular heights and inclinations; their design refers to the informal arrangement of large mature trees on the site. The branches are triangulated with the CHS roof members and lateral support is provided by fixing two branches back to the secondfloor slab of the adjacent classroom block.
The roof is composed of single-glazed 6.4mm laminated glass panels on 134 x 51mm aluminium glazing bars at 600mm centres. Glazing bar cleats are fixed to angle brackets welded to the CHS structure.
Four panels of glass form the roof slope, jointed together with silicone. To reduce solar heat gain, the two upper panels are laminated with a white translucent interlayer.
Rainwater drains into an aluminium channel fixed to the ends of the glazing bars.
The curtain wall is supported by a row of 139.7mm diameter CHS columns braced by horizontal CHS members.