Commercial & Leisure Award Winner 2016

Location: Westonbirt, The National Arboretum, Gloucestershire
Architect: Glenn Howells Architects
Client/Owner: Forestry Commission
Structural Engineer: Buro Happold
Main Contractor/Builder: Speller Metcalfe
Joinery Company: S H Structures
Wood Supplier: CTS Bridges, Ventis & Brasker Masten, Russwood, Heseltine Design
Wood Species: Scottish and Siberian Larch

The Grade I listed Westonbirt Arboretum is home to one of the finest tree collections in the world. The Stihl Treetop Walkway provides views over this landscape, in particular the ancient woodlands of Silk Wood and across The Downs. At almost 300m it is the longest structure of its kind in the UK. The walkway bridges across a valley, allowing for ease of access at ground level without any stairs or lifts. While walking along the structure the valley falls away beneath and the walkway rises to over 13.5m above the forest floor. The route snakes above and through the tree canopy supported by scissoring timber legs spaced at 10.5m intervals. At four points along the route it widens from 1.9m to 3.7m, providing spaces for pause and reflection. The walkway is a hybrid timber and steel structure. Larch was selected as the principal material given its durability and attractive colour. Scottish larch was selected for the decking and handrail while the columns are Siberian larch as it offers a tighter grain and higher strength-to-weight ratio.