Wolfson Tree Management Centre, Westonbirt
Timber was the obvious choice of building material for the new Wolfson Tree Management Centre at Westonbirt Arboretum. The arboretum hadn’t previously used their own natural resource in past building works so it was wonderful to use such locally felled timber in the creation of the tree management centre.
One of the buildings as part of the tree management centre project was the machine shed – a 35 x 20 metre building which is now used to house large agricultural machinery with easy access overhead doors. One hundred and forty year old corsican pine was used for the king post truss roof – felled, of course, at Westonbirt and partly hand hewn onsite as part of the Carpenters Fellowship program.
The project engineers, BuroHappold, said: “The design team’s initial response was to look at the forest resources available at the arboretum. By gaining an understanding of the timber that would become available through the routine management of the arboretum it became apparent that some significant sized trees could be harvested. These large timbers were used to create the 20 metre spanning king-post type trusses forming the Machine Shed roof, which include 20 metre long timbers forming the trusses’ tie members. Larch and Corsican pine were the main species used, with many other species used for cladding including coppiced oak and Douglas fir.
For the Machine Shed trusses, the intention was to use traditional connection forms where possible. However, due to the lightweight roof and large door openings, wind uplift loads on the roof would lead to substantial reversal of loads which many traditional forms of connection are not able to resist. Therefore many of the connections developed were a hybrid of traditional forms reinforced through the use of steel plates, bolts and screws and designed to ensure that additional capacity and robustness were achieved. Where possible, traditional mortice and tenon connections were adopted.”
In May 2017 the Centre was awarded three RIBA Awards: RIBA South West Award, RIBA South West Sustainability Award and RIBA South West Client of the Year.
We have been involved in a number of builds at Westonbirt Arboretum, read the Maples restaurant case study here.