Waugh Thistleton was one of the first architecture practices to begin exploring timber construction back in the early 2000s. Their first project was the nine-storey Stadthaus, also known as Murray Grove in London, completed in 2009 and boasting load-bearing walls and floor slabs as well as stair and lift cores in cross-laminated timber (CLT).
Pioneers in high-rise timber construction
It is no exaggeration, then, to call Waugh Thistleton pioneers – not only in timber construction, but also in building tall in timber. And when you are a pioneer, you will inevitably encounter the occasional sceptic.
Kirsten Haggart, deputy managing director at Waugh Thistleton, explains that the prejudices they faced in the early days are the same as those they encounter today. Fire risk and moisture problems were obstacles that many regarded as insurmountable. But Waugh Thistleton has demonstrated that these challenges can be addressed through carefully considered design, innovation and research. It is not about avoiding the difficulties, but about meeting them with the right tools and knowledge, she says.
“Many people assumed that building in timber would mean higher costs. But we were able to show early on that we are cost-neutral. Building in timber is faster, and the faster a building goes up, the shorter the financing period. That results in lower interest costs on loans and means flats can be let much sooner. It was a powerful argument in the beginning."
Shared knowledge and fire safety after Grenfell
Sharing knowledge about timber construction has been a common thread running through Waugh Thistleton's work. The lessons they have learned by overcoming problems and surmounting challenges are shared in publications such as the New Model Building Guide.
“That book is a direct response to the Grenfell Tower fire in 2017. We wanted to create an industry-wide guide on how to build multi-residential buildings in mass timber safely and in compliance with regulations in the UK,” says Kirsten Haggart.
Grenfell Tower was a building with a concrete structural frame and a façade of aluminium, polyethylene, plastic and foam insulation. The fire started in a flat, and the catastrophe – which claimed 72 lives – also led to the banning of combustible materials in the façades of residential buildings over 18 metres in the UK and residential buildings of all heights in London.
Waugh Thistleton proactively addressed the challenges head-on and contacted José Torero, a leading fire engineer from University College London, and NHBC, one of the UK's largest inspectors and warranty providers for housing.
The aim was to review NHBC's requirements and then collaborate with them, which resulted in a performance specification and 26 details that NHBC pre-approved. New Model Building can be described as a construction system for multi-storey buildings, with columns and beams without combustible materials in the non-load-bearing façade, which is pre-approved and permits the use of timber structures in residential buildings.
Because Waugh Thistleton openly shared their experiences, others can now use these details and methods, knowing they have already been through an approval process.
“Fire design in timber is a science, and innovative architects risk encountering varying assessments from fire safety inspectors and building control authorities, who often lack experience with the specific science behind timber structures. If they follow the advice in the New Model Building Guide, they can feel confident that their methods should pass through the approval process relatively smoothly,” says Kirsten Haggart.
Circularity and the wooden buildings of the future
Waugh Thistleton are pioneers in more ways than one. But although they are known for building tall buildings in timber, it is not something they actively advocate. According to Kirsten Haggart, it is not about building tall, but about building more in timber.
“One of the great advantages of timber is that buildings can be adapted when they reach the end of their lifespan. Timber can be disassembled and reused in a way that many other materials cannot,” she says.
Circularity was something Waugh Thistleton explored in the office building Black and White Building in London, which was also the focus of the Horizon-funded research project Woodcircles, aimed at increasing the circular use of timber in the construction sector.
“We truly see a future where timber can be part of a circular economy. By building with timber, we can create buildings that are not only sustainable during their lifespan, but also possible to reuse when they are no longer needed. It is time to change the way we build, for the sake of both people and the planet. Timber is a vital part of that change,” says Kirsten Haggart.
Text: Mattias Boström Images: Waugh Thistleton, Tog
