Solar Gain #4: Westminster Place
Westminster Place, London by Sheppard Robson
Estimated completion date
Gross internal floor area
Westminster Place is a fully glazed, 16-storey office building in London’s Waterloo which was recently granted planning approval.
A glass double-skin facade is being considered for a buffer in winter to increase the U-value, extend the mid-season margins to reduce energy demand and act as a hot-air flue in summer.
There are four distinct facade zones: external dichroic glass fins; an external single-glazed skin; a ventilated slot containing perpendicular diagonal structural glass fins, which support the external skin and provide a spiral chimney effect for the rising hot air; and an internal double glazed skin to accommodate internal partitioning and allow access for maintenance.
Early computer modelling of the double-skin facade showed that diagonal airflows move from facades with direct solar gain to those without. The 45m height and the limited width of the air gap suggests that the air temperature within the void will be unacceptably high at the upper floors, and could re-radiate heat through the internal skin during peak loads. This would mean increasing perimeter cooling
loads to maintain comfort levels.
In response to this potential problem, Sheppard Robson proposes sealing individual facade modules and using high-performance glass, greatly reducing the transfer of heat and removing the need for interstitial blinds or an opening internal skin.
David Ardill, design director, Sheppard Robson