The designers of the new headquarters for Stoke-on-Trent City Council, a building that will be the heart of the new Smithfield leisure and cultural quarter, wanted to create a landmark that combined modern design with references to the rich history of pottery manufacturing in the city.
Michael Metcalfe, commercial sales manager at Pilkington said: “As with much modern architecture, this building is really defined externally by its glazed façade, and the top priority was to ensure that the colours were as vibrant as possible.The resulting building is a vibrant kaleidoscope of coloured glass inspired by the work of world-renowned ceramic artist Clarice Cliff, who was born and worked in Stoke-on-Trent. Five colours, green, blue, red, yellow and white, all drawn from the colour pallet of Clarice Cliff designs, are arranged along all of the facades in a geometric pattern reminiscent of the potter’s most iconic pieces.
“Standard practice when creating coloured double glazing units is to apply the colour to face four on the inner pane of glass. However, this can reduce the vibrancy of the colour, due to added reflections from the outer pane.
“Because we needed maximum brightness, we digitally screen printed the colours onto face two – the inside of the outer sheet of glass. We also used Pilkington Optiwhite™ low-iron glass for the outer pane, which has a higher level of clarity and therefore allows the colours to be seen in their truest form.
“We then gave the colours a further boost by ensuring that the application was completely opaque, and this was done by applying a second layer of ceramic paint to the inside of the glass.”
The units that make up the façade all needed to be custom designed and manufactured to deliver the required pattern. The variation in colours across the façade meant that few units were identical to each other, and they had to be installed in a very specific order.
An advanced glazing system supplied by German manufacturer Schüco was used, which allowed the façade to be constructed off-site in 3m by 1.5m sections.
Michael Metcalfe continued: “The project was like piecing together a very complicated jigsaw. As well as virtually no two units being the same, and many of them incorporating electronic-opening vents, there were also other variations between the façades. For example, for those sides of the building with the most exposure to the sun – the south west and south east elevations – glass with a higher solar control rating was used to reduce the amount of energy allowed in to prevent overheating during the summer.”
The south-facing units, which are more exposed to direct sunlight, used Pilkington Insulight™ Sun with 60/33 specification while the north-facing sides, for which solar gain was less of an issue, used 70/39 – a glass that transmits more solar energy, but gives greater clarity.
The glazing was complicated yet further by the fact that on three sides the coloured panes are not flush with the clear glass but stepped out slightly.
Michael Metcalfe added: “The architects wanted the colours to not only be as bright as possible, but also to physically project out of the façade on three sides of the building, lending them further emphasis.”
A new landmark
At the front of the building on the ground floor there are double-height, single-unit windows that create a light and airy atrium space. At 4.6 metres in height, and spanning the width of the building, preventing overheating from excess sunlight was vital, so Pilkington Insulight™ Sun 40/22 was used for these units.
A total of 4,300sq m of glass was used in the building, 2,300sq m of it transparent and 2,000sq m featuring the screen-printed colours.
Client: Stoke-on-Trent City Council
Architect: Aedas RHWL
Main contractor: Laing O’Rourke
Installer: FK Group