Michael Laird Architects
Charles Henshaw & Sons Ltd.
£ 2.1 Million
The 1202 zone drained curtain wall system achieved the best air pressure test result, as part of a whole building pressurisation test, that main contractor HBG and Oxfordshire-based testing house Building Sciences have ever witnessed.
The system was installed by Charles Henshaw & Sons as part of a £2.1 million façade contract for Gyle Square, a speculative office development in Edinburgh designed by Michael Laird Architects for Highland Properties Assets (South Gyle) Ltd.
The building achieved a test result of 2.16 m3/h/m2 at a rate of 50 Pa. The target standard is for air permeability not to exceed 10m3/h/m2 at an applied pressure difference of 50 Pa. The test was carried out by Building Sciences in accordance with CIBSE TM 23 pressure test procedures, which form part of revised Document L in England and Wales and became statutory for buildings over 1000 square metres in October 2003. The test does not actually form part of the Scottish Regulations’ Document J. However, to ensure the long-term marketability of Gyle Square, Highland Properties felt that it was important to ensure a good, environmentally friendly air permeability result.
Gyle Square is a 15,500 square metre, three-storey building with a central, open courtyard. The 1202 zone-drained curtain wall system, featuring AA®601 casement windows, has been installed on all externally facing elevations. To the internal courtyard elevations, the system has been installed into rendered walls.
One particular design feature required by the architect of the curtain walling focuses on two of the building’s five flights of stairs. There are three ‘secondary’ staircases in the building and two that occur next to the two main entrances. These are actually external, ‘feature’ stairs and are bolted onto the building. Alan Macgregor, project architect, explains, “It was our intention to make the two external staircases as light as possible. We were looking for glass to glass corners and very little structure, which we achieved. The glass actually goes up right over the top of the staircase to form the roof and back down the other side. There is very little visible of the actual structural fixings from the curtain wall sections back to the structural steel, and the fixings themselves are quite discreet.”
- 1202 Curtain Wall
- AA®601 Casement Windows
Project Report (PDF):
- Gyle Square Project Report [202KB]