New College in Oxford isn’t new. It has been around since 1379.
In 1403, the college came up with the first purpose designed quadrangle - or quad – a square garden surrounded on all four sides by buildings.
They added an open ended, garden facing quad in 1685 which further developed the nature of educational spaces.
So, 621 years after the first planned quad came a new interpretation of the idea. Not angular, but curved – the new Gradel Quadrangles are a stone’s throw from this original of 1403.
The buildings are purposefully curved to define architectural space and enclosure. The curvature exists in both plan and section of the building, with a curved roof whose shape derives from the shape of an imaginary hanging chain, suspended upwards from the undulating tops of the curved walls.
The Gradel Quadrangles are three buildings; the Main Quad which accommodates student bedrooms and an auditorium, a smaller building with more bedrooms called New Wareham House which incorporates a tower overlooking Oxford, and finally the new porter’s lodge.
Each building features an undulating timber roof structure of interlocking timber beams, clad in unique tiles and set over a curving limestone façade with a hidden reinforced concrete frame designed to be as light as possible and shaped for the rest of the building to take its rippling form.
Tim Lucas, Partner at Price & Myers, tells us the project story through his eyes:
"Quads and tiles are both known for being rectangular. New College Oxford’s latest building has reinvented the idea of a quad in a curved plan.
Early explorations in the design centred around building a curved roof over the curved quad – a loadbearing vaulted roof, made of Catalan tiles cemented together with plaster of Paris.
This way of building, used by Gaudí and Gustavino, creates elegant, efficient structures, whose funicular shape is loaded compression; a vault can be vanishingly thin as a result. Sadly, the skills to build these roofs are also vanishingly rare and not practical to use on such a scale as the Gradel Quadrangles.
Looking for alternatives, sprayed concrete seemed possible but, with a large basement, we had enough concrete in the scheme already, where it was really needed. So we started wondering whether our vaulted roof could be made in timber.
We worked a few options using diagrids and CLT shells but the one that won out was simple curved laminated timber ribs skinned in OSB and planks. What was exciting was that the original craftsmanship envisaged in the tile layers making the vaults became digital craftsmanship, the timbers slotting together into shaped rebates with no need for steel connectors. (continued below)
The project concluded eight years after it began with the idea of tiles again, this time not to hold up the curved roof but to clad it. Working with the architects and contractors, we developed a method to clad the roof with 5,000 or so aluminium tiles of different shapes, devising a way to lay them out over the irregular surface, with installers using their phones to map the positions with an augmented reality app.
The other curves of the building are rendered in structure: the concrete frame cradles the curved floor plates and the stone walls, made in Ancaster limestone, dovetail together like the stones in a lighthouse wall."
Watch this space for a deep dive into the technical challenges of the project in more detail, coming soon.
