Westonbirt Arboretum TMC - Blog - Invisible Studio Architects

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The new Tree Management Centre for the Westonbirt National Aboretum in Gloucestershire is a big span workshop building, a new mess and educational facility, and a yard for the tree team. The critical ambition was to take advantage of the timber that Westonbirt have, and design a series of buildings that use this timber intelligently that could act as prototypes for rural buildings elsewhere, and, in terms of the Machinery Store, offer a big span timber alternative to the steel or concrete framed ‘Atcost’ rural barns.

We worked with timber specialist Charley Brentnall and engineers Buro Happold on 2 key buildings. The first, shown here, is a big span workshop that uses 20m long Corsican Pine members in continuous lengths. These members were hewn by hand into the requisite structural sections. The building was constructed entirely from green timber grown and milled on site at Westonbirt, with a series of interns and apprentices from the Carpenter’s Fellowship. The students were up-skilled through the process of working alongside master carpenters. The project built upon design processes and construction methods that have evolved through the construction of the Caretakers House and Visible Studio. It has recently won a National RIBA Award in addition to three RIBA Awards including an RIBA Award and has been shortlisted for the RIBAJ Mackewen award. It also received a commendation in the Structural Timber Awards. We issued this statement after the RIBA Awards Ceremony describing the process:

We are thrilled that our Tree Management Centre for Westonbirt Artortetum won three RIBA Awards last night: An RIBA Award, the RIBA Sustainability Award and the RIBA Client of the Year Award. This is a testament, we feel, to a remarkable project.

The project at Westonbirt – for the Forestry Commission – was won by us through a formal government tendering process and we included Charley Brentnall as part of Invisible Studio – the design team – pre contract, before he went on and won the formal tender to act as main contractor for the larger of the two projects, the Machinery Store. Charley ran a course early on with volunteers to hew the enormous Corsican Pine into the main structural members, before leading the construction phase for the Machinery Store with his extraordinary team of carpenters from Carpenter Oak & Woodland and NVQ Student Carpenters, and the smaller of the two buildings was let to Nick Perchard and Jim Symon (who were originally trained by Charley) who then then led a wonderful band of Westonbirt Volunteers in the construction of the ‘Mess Room’ welfare building, many of whom have gone on to use these skills gained from Nick and Jim in their own projects.

The engineering by Buro Happold was deceptively complex: the main timber structural members are possibly the biggest ever in UK Construction (Certainly for 150 years), and very few engineers have the nous like Andrew Wylie and Graham Clarke to understand how to use the unpredictable, ungraded, un processed, untreated timber directly from site. The Sustainability Award that we gained is testament to their thinking.

And finally – the Client of the Year Award for the Forestry Commission means so much when – as the jury citation said – this is a client that totally owns these buildings now, and fully supported the experimental, risky and unpredictable way of working that we espoused from the outset, where an option would have been to have put up a few steel portal sheds. Westonbirt had never used their own timber in any of their buildings before, and certainly nothing on this scale.