The Hive, FCB Studio’s library in Worcester which opened in 2012, acted as an introduction to CLT for the practice
Photo – FCB Studios

St Luke’s Primary School, Wolverhampton, by Architype, won awards and helped introduce timber in the wave of
school buildings in the second half of the noughties – Photo – Architype

Left, Northwoods Design’s Aultbea House. Right, Dualchas Raasey Community Hall, both part of the Highlands
& Islands return of timber of the last fifteen years – Photos – from the practices

Architecture and timber in the UK.

Wood in construction, and especially structural timber-based architecture, has experienced a revolution in the last twenty years, moving from the margins to the almost mainstream. The fortunes of what in the 1990’s was still a seriously unfashionable building material has been turned around by a mixture of timber build showcases, an awakening to increased environmental threats and heightened by climate change, the accompanying toughening of energy and carbon regulatory standards, alongside the rise of engineered timber, and particularly Cross Laminated Timber (CLT). This has been particularly pronounced in Britain, where one time wholesale indifference across much of the British architectural scene has undergone a major conversion experience, propelling an exponential growth in timber buildings since the turn of the millennium and intensifying through the last decade.

The turn of the millennium saw a wave of showcase timber buildings across Britain, from new national assemblies in Wales and Scotland, experiments in gridshell and related lightweight shell and space frame structures, including the Weald & Downland Open Air Museum, Savill Gardens, the Earth Centre in the North East and Cornwall’s Eden Centre Project. These high-profile projects were further underlined by the large-scale renewal of school building infrastructure, which saw sustainability climb up the agenda, and a wave of primary, secondary schools, and the relatively new academies, built from wood. Primary schools like Architype’s St Luke’s in Wolverhampton, and White Design’s Kingsmead in Cheshire, dRMM’s CLT Kingsdale school sports and music hall and R-SH & Partners Academies  programme launch timber showcase, Mossbourne Community Academy, in South and North London respectively, all marked a way towards 21^st century timber based sustainable education infrastructure. Furthermore, by the end of the noughties, the beginnings of medium rise CLT housing with WaughThistleton’s eight storey Murray Grove and  Karukasuvic Carson’s Bridport House added to the architectural and engineering excitement around CLT and in the process highlighted North London’s Hackney, a buzzing hub for this new timber architecture. Office building showcases like Hopkins’ WWF Living Planet headquarters by Hopkins and FCB Studios Woodland Trust’s Grantham HQ brought further attention to engineered glulam and CLT. In Scotland, a different though parallel return of timber story was being played out, with a network of smaller regional North West Scotland Highlands & Islands practices , such as Northwoods Design, Dualchas, Rural Design, Gokay Deveci, and Makar, all increasingly working with home grown Scottish woods, and helping timber manufacturers grow a viable local wood materials sector in the High North.

This momentum has been gathering at an accelerating pace over the last five years, with more and more timber projects either being completed, on the screen-face or being announced, including large scale housing, schools, academies, Higher Education projects, and showcase offices. Across London – and particularly in Hackney – and in many parts of England, the number of new CLT housing and office buildings being completed have almost turned this wave into the new normal. CLT has merged with the pre-fabricated modular housing agenda, and several factory type housing production facilities have opened or under construction in different parts of the country. Even practices long associated with other industrial materials are taking up timber, for instance, Zaha Hadid are working on the first all timber football stadium. There are challenges, not least new legislation in the aftermath of the Grenfell Tower tragedy, which has seen understandable concern regarding timber as a flammable material and has brought to an almost complete halt the commissioning of timber buildings above 11 metres tall (three stories.) Many across the timber sector have sought to communicate that structural timber’s behaviour in fires – it chars at a slow rate so that structures remain intact and standing, unlike steel, which can melt and collapse in high temperatures, for the required fire safety periods – makes it safer than popularly perceived. There is frustration that the legislation tarnishes structural timber with the same brush of more concerning and proven flammable construction systems, while across Europe and North America tall and larger timber is advancing apace. The sector is currently organising tests and trials to demonstrate structural timber’s safety, and one can envisage that tall timber will likely emerge again in Britain before too long, although at present it has come to a full halt. Where this new legislation hasn’t stymied timber use across the many lower rise building typologies, although here again there are issues primarily around insurance concerns. All this said, what remains clear is that the case for timber in British architecture, not least related to zero carbon, as much as in projects realisation has been persuasively made, so much so that timber has effectively crossed a threshold from the margins to the mainstream.

Projects

Cambridge Central Mosque – MarksBarfield Architects – the first contemporary ‘eco-mosque’, features large numbers of engineered glulam as a key highlight for its calligraphic timber tree columns throughout the buildings, along with structural CLT in its walls and roof.

With timber becoming more popular and the number of projects increasing year on year, what was experimental engineering and architecturally adventurous is becoming the accepted mainstream. Therefore, current and new architectural projects don’t quite carry the same surprise punch of the early pioneering ones. Still, here are some examples of new, recent, and up and coming projects.

Here are several striking recently completed timber roof systems.

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See the in-depth Unstructured Annular article on the Cambridge Mosque project here.

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Zaha Hadid’s timber entry-point – Forest Green Rovers, the only all vegan football team, apparently – Render – Zaha Hadi

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Architype – Harris Academy Sutton – the first certified Passivhaus Academy in Sutton, South London, employs extensive CLT and engineered timber as its core structural material

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Macreanor Lavington Architects – Ibstock school new refectory building – in West London features an expressive and striking timber wall and roof work surrounding a glazed lantern.

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The Peter Hall Performing Arts Centre Tr– at the Perse School’s Performing Arts Centre in Cambridge, HowarthTompkins have integrated a diagrid roof into the triple storey foyer area.

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Flimwell Park – The Architectural Ensemble – in the process of being completed (aiming for autumn 2021), a whole suite of timber buildings on one site on the easterly edge of Sussex. Comprising eight artisanal accommodation units, workshops and a restaurant.

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Homerton College dining hall – Feilden Fowles Architects – another Cambridge project, at Cambridge University, due to complete in 2021, includes an elaborate timber frame intended to draw the 19^th century Arts and Crafts Movement into the present day.

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Charlton Workstack – dRMM – the CLT pioneers have developed a five-storey stacked CLT structure for their South London work place centre, Charlton Workstack, each floor cantilevering further out over ground floor level. Dependent on the outcome of the flammable materials review, Workstack will be on site and complete in the next 18 months.

dRMM’s CLT and timber story is told in the way sexier building material  feature in Unstructured extra 9.