Design excellence

University of Wales Trinity Saint David in Swansea has invested £15m 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 stunning twin wall facade featuring AluK curtain walling systems, complementing and adding a new dimension to the original design.

The modern, double skin facade extension provides additional 657 m², 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, Powell Dobson, said: “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 facade runs the full 38 m of the Alexandra Road elevation. Designed by D2e, a multi-disciplinary engineering and management consultancy, the facade 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.


The gap between the internal and external wall allows to control the flow of air and temperature within the building interior, 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 heating costs, while in summer, when overheating can be an issue, windows can be closed and heat rejected using mechanical ventilation.

Banks of bespoke, top hung, open-in AluK 58BW window system are located 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.

With a visual sightline of 60 mm and a mullion depth of 150 mm, the SL60 ensures that stringent aesthetic parameters set out by the architect were adhered to. The horizontal Vierendeel members, also designed to incorporate a 60 mm face, ensured that the requirement of visual transparency of the main facades was attained. With demanding structural requirements, the 150 mm deep mullion was adequate to conclude and surpass the project specification.

Internally, the SL60 system seemingly spans 12 m unsupported between structural columns. The support comes from a bespoke design of the aluminium Vierendeel Truss 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 Brise Soleil blades which run the full width of the building following the spectrum of the rainbow.


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