University of Wales Trinity Saint David in Swansea has invested £15 million into the refurbishment, restoration and extension of the Grade II-listed former Central Library building to create the new Institute for Sustainable Design. Devised by Powell Dobson Architects, the development incorporates a twin wall façade featuring AluK curtain walling systems, complementing and adding a new dimension to the original design.
The extension incorporates a new reception entrance
The modern, double skin façade extension provides additional 657m2, and incorporates a new reception entrance off Alexandra Road, workshops, teaching spaces as well as design studios. The original circular reading room has been restored and made available as a public venue.
Yvonne Gibbs, architect at Powell Dobson, comments: “Due to the context of the Listed Building, it was imperative that the new extension was as transparent as possible to express the original scale and features of the historic fabric behind. The University was also looking for a truly sustainable solution, to both reduce energy consumption and create an inspiring place to learn.”
As the main extension to the Grade II listed building, the twin wall façade runs the full 38 metres of the Alexandra Road elevation. Designed by D2e, a multi-disciplinary engineering and management consultancy, the façade comprises AluK SL60 curtain walling system forming the internal wall, and structurally bonded glazed toughened laminated glass skin forming the outer wall, with an interstitial space between them.
“This arrangement provides the transparency that the Listed Building deserves, whilst introducing a number of opportunities for passive climatic control,” says Yvonne Gibbs. “The facade is south facing and therefore through solar gain the space between the two skins heats up naturally. This in turn acts as a thermal buffer, which keeps the building warm in winter months whilst promoting air movement and cross ventilation during warmer periods. It also facilitates the introduction of fresh air into the space, which is attenuated through a series of louvers at the base of the facade to temper noise pollution from the busy road outside.”
The gap between the internal and external wall allows the flow of air and temperature within the building interior to be controlled, using the air exhaust louver on top and the air inlet louver at the bottom to create a ‘chimney’. In winter, solar gain can be collected in the buffer zone, brought into the building and offset the heating costs, while in summer, when overheating can be an issue, windows can be closed and heat rejected using mechanical ventilation.
Windows on the internal wall open and close automatically depending on weather conditions, regulated by sensors located on the face of AluK’s SL60 curtain walling system. Manual operation is also possible to introduce further air.
Internally, the SL60 system seemingly spans 12 metres unsupported between structural columns. The support comes from a bespoke design of the aluminium walkways, fixed at floor positions and supported by hanging stainless steel rods that are structurally retained in tension. These in turn act as a carrier for the glass blades, which run the full width of the building following the spectrum of the rainbow. Yvonne Gibbs continues: “They are multi-functional; environmentally, they protect the occupants and their computers from glare and they reduce over-heating. Their multi-coloured appearance, created in conjunction with a local glass artist from the application of a nano-technology coating, also signals the creativity and aspiration of the University within.”