Practice founders Katerina Dionysopoulou and Billy Mavropoulos on working with specialists in concrete, architectural metalwork, bricks and glass made from mussel shells
For our Interlock building in London’s Fitzrovia, we wanted to create a brick facade that looked handcrafted with bricks that appear to be pushing inwards and rotating like cogs.
We approached the R&D department at building products firm Forterra, who we’d worked with eight years before on an idea for a lattice brick arch, which never happened, but we went back to them with a render of our design for Interlock to see if they could help.
Forterra was amazing. We worked out it would require 5,000 different bespoke bricks, which would have been far too expensive. They looked at using proprietary products to achieve a similar look but the result didn’t look like cogs anymore, so we visited the factory to better understand how the production process worked.
While we were there, we came across a pile of discarded metal dies used for creating brick specials, and learned that making these was the expensive part of the process, not the cutting of the wet clay once it comes out through the dye. So we looked into rationalising the number of unique bricks required by modelling every single one in 3D.
In this way, we worked out we would need dies for just 14 unique bricks and then cut the wet clay in order to create a further 44 in order to achieve the variation required. There were a lot of intricacies and a lot of parameters that we had to consider, and it took a long back-and-forth conversation over two months to finally resolve the design and deliver it within the proposed budget.
It was a great collaboration. As architects, you have to put in the effort to make fabricators, suppliers and consultants want to work with you in this way, and ensure that they know the potential value of the outcome from the get-go.
We worked with architectural metalwork specialist John Desmond on the interior design of The Gaslight, an art deco building in London’s Fitzrovia that was being refurbished as flexible workspace. Our biggest intervention was an intricate metal screen to mask the concrete lift core, spanning four floors. We looked into 1920s patterns, especially those used on lift doors, and came up with a design that combined a 2D layer around the core with a folded 3D layer over that. This gave a sense of the concertina effect of old lift doors.
We had an incredible collaboration: the people who worked on the project were mathematical perfectionists, and the company could really see the potential of this design as a marketing tool.
We first did a mock-up using water-jet-cut bronze, but when we folded it, the metal cracked because of its high percentage of copper. So we changed to PVD-coated stainless steel, which could give deep hues of bronze, was more robust and easy to maintain and clean. We also decided to laser cut it to create the pattern, as it was cheaper than water-jetting, but this process created very sharp edges.
Through discussions with John Desmond, we found out that if the speed of the cutting was changed, it was possible to cut more gently to get a softer effect. But this would have also been more expensive. So together we worked out how we could reduce costs by prioritising which areas needed slower cutting. We made several small mock-ups and did more joint tests, visiting the factory in Wimbledon many times and reviewing the drawings before anything was cut and folded.
Then we looked into the different finishes we could achieve and did three or four tests with a wax that could mask all fingerprints. Removing them completely gave quite a dull effect, so we settled on using just enough wax so that you could see some of the finger marks and get a pleasing patina.
At the beginning of the process, we agreed with the client that the lift core skin would be removed from the main contractor’s remit, and handled as a separate installation. At the end of construction, the John Desmond team came in and took three days to hang the 66 different metal panels. They were proper craftsmen who took a real pride in what they were doing. They understood exactly what we were after and were constantly making suggestions and coming up with solutions. We’re now working with them again on displays for a travelling jewellery exhibition.
David Bennett is someone with unrivalled knowledge of concrete. We turned to him when we wanted to create concrete with quite a bit of ornament for our Cast House in south London. Our design played on key features of 1930s houses, such as the gable, porch and bay, and included a series of cascading, cast concrete boxes with cornice details that appear pushed into the brick facade.
We had a dialogue with David about what we could do to achieve the effect we wanted; we hadn’t used concrete before in that way and had a huge long list of difficult questions. He’s a real master of the art and was willing to explore all sorts of ideas with us. He produced sketches that looked like joinery shop drawings, right down to how to make, fix and finish the timber shuttering for the cast elements.
Part of the conversation was about the best material for the formwork, and we played around with different plies and textures before ending up with softer timbers for the moulding detail and slightly harsher timbers for the main walls. We also had many conversations about mix and finish, brushing back the edge of the concrete planters that lead down to the basement, to give a textured finish.
The concrete was cast in moulds in-situ and mechanically fixed into place. David was exceptional in guiding the people doing the concrete on site – he was there almost as a teacher. You can’t see any holes in the end result because he showed the contractors how to invisibly infill them and then paint over. We made over 12 different samples of paint colours to match the concrete at every point so that the filled holes become invisible.
Lulu is a material futures MA student at Central St Martins who has created a glass made from mussel shells. We were invited by Here Design to collaborate with her to create an architectural response to her research. This was exhibited in the exhibition Beautility: How Fusing Beauty and Function Can Change the World, held in May.
This was an amazing opportunity for us to learn about glass, which was a new material for us to research. Lulu has come up with a unique recipe to create glass from quagga mussel shells, an aggressive non-native species that causes blockages in Thames Water tunnels. Thames Water has to remove them and they normally end up in landfill so her invention is a sustainable solution to that problem. She has crushed the shells, mixed them with local sand and experimented with different ratios to create cast-glass tiles with different hues and effects.
She came to our studio, showed us her samples and we worked with her and a glass blower to understand the process of making. We like working with the restraints – there were so many things to explore such as colour, aggregate and thickness.
For our architectural application, we explored lost Thames industries and identities. We stumbled upon the fact that Royal Doulton made pipes for the sanitation system and also produced ornamental terracotta, such as that used on chimney pots. We became interested in these patterns and used them in moulds to cast glass tiles. Our proposal uses these to recreate the form of three lost pubs on the north bank of the Thames.
At the moment, the application of Lulu’s glass is still at an explorative level. Perhaps the glass could potentially become a viable cladding material if laminated with another piece of laminated glass – there’s a lot to explore.
We enjoyed the process so much. It was fast-paced, so interesting and really kept us on our toes. It was great to work with an energetic young student who could bring a fresh approach as someone who wasn’t part of the architectural world. All in all, we’ve loved it and will continue exploring this further with Lulu. It’s opened up a world that’s so new and exciting for us.
As told to Pamela Buxton