Wizards of timber: working wonders with wood

Xylotek specialize in delivering “non-standard timber structures that need innovative solutions”. Their self-proclaimed mission is “to change the world with wood”. We spoke to co-founder Martin Self to find out more about their highly distinctive work..

Browse Xylotek’s many projects and you’ll encounter a truly eclectic portfolio: from the award-winning ABBA Arena to Jain temple canopies in Gudjarat, alongside a feature CLT staircase for Netflix’s London HQ.

Xylotek work in many capacities: as specialist consultants, subcontractors and sometimes design-build contractors in their own right. The practice was founded by Charley Brentnall with Martin Self and Oscar Emmanuel. They met at Hooke Park – the Architectural Association’s woodland campus in Dorset – and bonded over a desire to take on technically ambitious projects, making a broader use of timber than the norm. Based in Bristol, Xylotek has grown steadily over its half-decade of existence.

Timber sorcery in the gridshell realm

The undulating, shell-like structure that is Westonbirt Arboretum Pavilion; all images © Xylotek

Their smaller-scale work has often sat within what Martin describes as “the gridshell realm”.

“There’s a particular use of ‘geodesic logic’ that we are good at: taking straight strips of wood, bending, twisting and manipulating them to make freeform structures,” he elaborates.

Their Sherborne Gridshell was a glazed gridshell for the entrance hall of a manor house with a unique double-curved geometry. Their Osnaburgh Street Pavilions – three lattice structures designed to sit outside British Land’s office campus in London – used thin strips of oak which were bent and laminated into their curved shapes. These laminated strips were then layered to make the lattices, before further layers of loose laths were added onsite.

“We carry out bespoke glue lamination in our own workshop. There’s something efficient in how we’ve been pursuing it – taking fingerjointed lamellas, glueing them up into laths and manipulating them into freeform net-type surfaces in wood. In the glue-up you define the shape in a way that constrains or describes the path that those lamellas can take – so they have a natural flow.“

The undulating, shell-like structure of the Westonbirt Arboretum Pavilion used a different technique but is “in a similar ballpark”, Martin says. He is particularly fond of this project because of the way it was approached. The client – Forestry England – set it up as a community build. Architects Invisible Studio worked with community groups to help design it, running modelmaking workshops.

“It was really rewarding to watch,” Martin recalls. “And all the wood was sourced from the immediate surroundings at Westonbirt. It was all felled, processed, steam-bent and assembled within a few hundred metres.”

Members of the Xylotek team, at their Bristol headquarters

Stepping up: the ABBA Arena

“Working on the ABBA Arena has been an amazing experience – it was a big step up in scale,” Martin enthuses. “It was a chance to bring our approach to a big CLT project.”

The arena, located in Stratford, London, hosts the ABBA Voyage concerts – the Swedish pop group’s ‘virtual’ gigs, which have become a top London tourist attraction.

It is designed to be demountable for future relocation. Xylotek worked on the auditorium, which forms the seating areas for the concerts, as well as incorporating entrance and bar areas, vertical circulation, fire escape corridors, and technical zones. They also carried out the production of the external timber rainscreen.

“When we joined the project it was a steel frame with timber panels within it,” Martin recalls. “But we advocated to move it to full CLT. And we were able to model it in way that could smoothly go into fabrication.”

“Most CLT is built pretty orthogonally, but this is built in a hexagon. There’s a huge amount of different angles, and almost every component is different.”

Designed to be taken apart

Installing the ABBA Arena

The arena only had a short planning permission for the site and the structure needed to have the potential to move on elsewhere. From day one, their model included assembly sequence information: it was organized by layering the sequence of the build. “Without doing that you wouldn’t be able to use the kind of details that would allow it to demount,” Martin states.

They carefully considered screws, avoiding ones that would be difficult to remove, and using Idefix blind bolted connections for the ledger board detailing – allowing things to be bolted in areas where you can’t access both sides.

“Timber is already so much better than concrete when it comes to disassembly,” Martin notes. “You can always take it apart, unless you are doing gargantuan amounts of glueing. So it’s about the nuances: avoiding ending up with bits of wood that have metal permanently stuck in them – hard to rework. Think ahead about ease of access for disassembly: the sequence of taking down as opposed to just putting it up.”

Pavilions on the Palitana pilgrim trail

Among their current projects is a fascinating collaboration with Arup, SJK Architects of Mumbai and Expedition Engineers. Xylotek have designed and are now installing two canopies within Jain temples at foothill and hilltop sites in Gujarat, India.

The elements were fabricated by strategic partners Simonin, in France, and Xylotek’s installation team are leading the build on site. The canopies provide solar shading, and are formed using glulam posts and CLT roof components. As part of the brief, there are no visible steel elements to this design. This lets the timber aesthetic sit comfortably within the hill site and the marble of the temples.

The structure is a reciprocal frame: each beam is supported part way along an opposite beam, which in turn is supported by the first beam.

“It’s an amazing location, but quite a logistical challenge. The temples’ site is on a pilgrim climb. So all the material and equipment have to be physically carried up and down. 150 people from the local community have helped, and our team had to do the hour-and-a-half pilgrim walk every day.”

From the outset, the climate had to be considered. The canopies use pressure-treated pine to be termite resistant.

A broad mix of skills and an eclectic portfolio

The Xylotek design team has a wide range of skill sets, so it can contribute to concept design, form-finding
and handle complex geometric modelling.

“Timber is definitely a growth sector – there’s more and more ambition to be building with wood. Architects and clients want to do it. But you do see projects falling back on steel solutions because they haven’t found the right route.”

They often find their way into projects via an architect or engineering contact – a practice who has advised the client that extra expertise in the mix.

Because Xylotek aren’t tied to a particular manufacturing plant, they are not trying to sell a particular product and aren’t constrained to any particular type of configuration. They can be agnostic about the technology used or the choice of wood species – it’s whatever works best for the project.

“Our portfolio is increasingly bringing work in, leading to other jobs,” Martin states. “We want to enable our clients’ ambitions – let them carry out more interesting and advanced work. We want to work with the best architects, the best suppliers and the best engineers to make great projects happen”.