Sustainable gold aluminium facade for stunning landmark Aliva UK was commissioned to develop an eye-catching, 3D-effect façade that would bring vitality to a hospital parking ‘super-hub’ for visitors. Architect Sheppard Robson’s brief was to extend the existing Grafton Street car park and create a striking local landmark for the Central Manchester University Hospitals NHS Trust’s complex, which cares for a million patients every year.
The stunning gold anodised aluminium façade was a Finalist in the 2017 Surface Design Awards.
The brief The car park building is normally seen from the side, not face-on, so the architects wanted cladding that would ‘step off’ the building, pushing out a further 800mm.
Sheppard Robson specified a metal façade that would not only enhance security, but also provide a minimum 75% natural air-flow to help the building breathe without the need for mechanical ventilation. This was a vital consideration due to exhaust fumes in the car park.
The architects also wanted each cladding panel to be exactly aligned with a parking bay, giving every vehicle its own gold façade. As well as the aluminium mesh cladding that spanned the floor spaces of the car park, the architects wanted silver horizontal bands to encompass the building on every other floor.
The final aesthetic challenge was to meet the planners’ and architects’ requirement for a visual ‘story’ for the building at ground level. Working with Sheppard Robson’s initial design, Aliva UK developed a gold anodised aluminium expanded mesh façade that stood away from the building to create depth and impact. The gold panels of mesh were each folded to a crisp point, resulting in a façade that could be seen at every angle.
There were several technical challenges that the team addressed through innovative technological design and experimentation:
Achieving the right finish Expanding aluminium and punching it with apertures weakens the metal. Folding it to a perfectly crisp point weakens it further. Aliva UK needed to find a combination of the right aperture sizes and folding techniques to ensure that the cladding allowed enough ventilation, looked perfect from an aesthetic point of view, and also maintained its structural integrity.
To do this, they tested a variety of aperture sizes and folding techniques. The tests needed to show that the cladding could withstand the worst of the elements – rain, wind, snow. At the same time, each fold needed to be perfectly crisp, so that when seen from below, each panel would be exactly aligned. Through prototyping the team were able to arrive at the final specifications and design.
Installation of the cladding Aliva UK’s original plan was to secure the cladding to the floor slabs of the car park; however, this was not possible for two reasons. First, the building was on a gradient. This meant that if the silver horizontal bands specified for every other floor were fixed to the floor slabs, they would also appear to be sloped, which would not create the right aesthetic.
Second, it was found that if a car were to hit the internal crash barrier at maximum speed, the crash barrier would deform out to 138mm. This meant that the cladding could not be installed against the building in the normal way.
To resolve these issues, an entirely bespoke fixing system was designed. This involved hanging the cladding panels from wind posts, meaning that the cladding was wrapped around the building, without being supported by it.
Despite there being minimal physical interaction between the internal structure of the building and the cladding, the cladding still had to interact with the inside of the building to meet the requirement for each panel to be exactly aligned with a parking bay. The Aliva UK wind post solution was able to meet this challenge too.
Screen printing To create a visual story at ground level, as specified by the planners and architects, Aliva UK’s design for the façade base featured a bespoke, screen-printed urban landscape that created a focal point for visitors arriving at the hospital by car.
While screen printing on intact panels of cladding is comparatively straightforward, ensuring that the images still appeared recognisable on mesh was one of the key challenges here. Again, prototyping helped the team to achieve the desired finish. The final look was achieved by first expanding and anodising the metal, then building up the screen printed design in several layers.
What the architects say Mark Antolak, Project Leader at Sheppard Robson said: “We worked closely with Aliva UK on the design for this important façade. Using our concept drawings, they undertook early prototyping work to ensure the design intent and quality were maintained all the way through to installation.”