Roundhouse Works is a creative centre designed specifically for young people. It’s an impressive project all round, which takes a hybrid structural approach by using cross-laminated timber (CLT), glulam and concrete to provide a range of different spaces. But the most novel aspect of the Roundhouse Works story is what’s on the outside: it is clad with railway sleepers.
Bringing circularity to Roundhouse Works; © Fred Howarth
The building makes use of space on the raised service yard behind the Roundhouse itself – a live music and arts venue in Chalk Farm, London. The new building sits in the former railway sidings that once served the adjacent railway lines. At Roundhouse Works, young people can learn about everything from digital entrepreneurship to circus skills. Reed Watts architects were employed as Executive Architect with Paddy Dillon on the scheme designed by Allies & Morrison.
Questioning the proposed metal cladding
The cladding was originally specified to be cast steel panels. This struck Reed Watts Architects as unnecessary in terms of both cost and carbon.
“It would have been a lot of metal for rainscreen cladding,” points out architect Matt Watts, Director and Co-Founder. “And there were other practical constraints in that not many cladding contractors would be used to that – there would be a cost premium.”
Reed Watts carried out a number of studies looking at other materials, before eventually taking inspiration and ‘proof of concept’ from 6A architects’ Cowan Court project at Churchill College in Cambridge. Completed in 2017, this had made used of reclaimed French railway sleepers for cladding. “We wanted to use UK railway stock, rather than importing it,” Matt tells us.
“Colin Rose, founder of UKCLT and working at Reed Watts at the time, led the sourcing of suitable sleepers to establish whether it would be cost prohibitive. The idea had added appeal because the Roundhouse itself used to be a turning shed for the nearby railway – it’s where the engines would turn around. And, as we were aiming for a BREEAM ‘Excellent’ rating, we knew it could improve the project’s upfront carbon.”
Colin found a supplier, and it became clear that many railway sleepers would be unsuitable. Some are made from creosoted oak or Scots Pine, which would be fine in terms of durability; but creosote is a highly flammable material.
The Roundhouse Works provide an essential creative outlet and stepping stone for young people in north London; © Fred Howarth
“So we wanted something that was untreated. The company that we were speaking to, Railway Sleepers Ltd, take stock from the UK rail network, and offer what are called relays, which are high-spec sleepers that are designed to be relaid in different locations. That’s what we specified, made of Australian Jarrah wood.”
After they arrived, Reed Watts also sent off a sample from one of the sleepers to be lab-tested for petrochemicals, just to make sure that the sleepers were indeed free of any flammable treatments. The tests were comprehensive, and found no petrochemical traces.
Making the most of each sleeper
The boards are fixed to hardwood battens on an aluminium helping hand system, fixed to the CLT.
Colin Rose looked at optimizing the use of each sleeper. They are chunky blocks, and it became clear that if the faces were cut off then each sleeper could go further. Wider boards were used in some areas of the façade; and the thinner offcuts were used in others. There is also a pleasing contrast in colour to the sections that used the virgin timber from the middle of the sleepers.
“If you look closely, you can see the tripartite holes where metal ties previously held the sleepers in place,” Matt says. “Before the sawmill cut the timbers down to size, they checked the holes for any remaining metal. Quite often there were bits of the threads from the bolts stuck in them, or occasionally half a bolt or two left in there. Obviously, the sawmill didn’t want to ruin its blades.”
A lived-in look
“The cladding subcontractor was conscientious and enthusiastic. They would take me around every every week, and we’d reject a small minority of the timbers if any had rotten parts in them. But minor, superficial damage – the occasional dent, a little spray paint on some of them – was acceptable.”
“The marks from its former life add character. You can tell which were the bottom and which the top of the sleepers: the underside ones have a few dents from where they sat on the stone chipping; the top ones are smooth and have a few rust patches from the plates for the railway track.”
© Fred Howarth
Traditional timber cladding will naturally weather into a silvery grey over time. The project completed in June 2023, and it’s interesting to note that most of the cladding has stayed the same colour as it when it first went up – apart from the virgin timber from the inside of the sleepers.
“The cladding section that used that particular wood was originally a rich orange-pink colour. As we knew that that section would change colour we applied SiOO:X, a product supplied by Russwood, which eliminates differential weathering.”
Putting minds at rest
“The clients were happy with the idea of using reclaimed timber cladding,” Matt says, “although the planners did have a few reservations – not least because the existing planning permission had been for the previous specification of metal cladding. We put together a document for them that demonstrated it would be safe, addressing fire concerns, acoustics and similar matters. It showed that the Jarrah would be durable and referred to multiple British Standards. The insurers asked a few questions, and I’m sure the document helped.”
The project had a model client in the Roundhouse Works team. There was already a bedrock of trust between them and Paddy Dillon, the architect they brought the project to. Furthermore, as a creative organization they acknowledged the inherent value of doing something a little different.
© Fred Howarth
“The Roundhouse Works houses the Centre for Creative and Digital Entrepreneurs, which is designed specifically for 18-30 year olds,” Matt points out. “The building is a centre for talent development, whether it’s entrepreneurial or music-related or circus skills. So the clients wanted something distinctive.”
And the end results are indeed distinctive – it’s a unique exterior with a pleasingly poetic connection to the site’s past.
Other TDUK members who worked on the Roundhouse Works project include Stora Enso, who supplied their Sylva™ CLT Floors and Roofs, Sylva™ CLT Stairs, Sylva™ CLT Walls for Roundhouse Works.
Read other timber re-use stories:
Can old timber be reincarnated… as glulam?
InFutuReWood: use and reuse of wood building components
A beacon of sustainable reuse: reclaimed timber groynes
