The Stihl Treetop Walkway
Credit Paul Box
Shortlisted in the Tourism & Leisure and Infrastructure categories of the RICS Awards 2017 is the Stihl Treetop Walkway – the new crowning glory of redevelopment at Westonbirt, the National Arboretum near Tetbury – and the UK’s longest treetop walkway.
The project to create the 300m long walkway was commissioned by the Forestry Commission as an architectural competition in 2009 won by Glenn Howells Architects and BuroHappold Engineers. The main contractors were Speller Metcalfe, the main fabricators were SH Structures.
Westonbirt, the National Arboretum holds one of the finest tree collections in the world, carefully laid out within a beautiful Grade I listed historic landscape.
The Stihl Treetop Walkway provides stunning views over the ancient semi-natural woodland of Silk Wood starts and finishes at ground level to provide easy access to all visitors. It uses the existing topography to give visitors a new perspective and views of the valley 13 metres.
The route takes the form of a sinuous ‘S’ shape, winding through the tree canopy with 57 crossing timber legs of solid larch and Douglas fir of gentle tapering cigar shape, equally spaced at 10.5 metre intervals holding the walkway in the air. At four points along the route the walkway gently widens from 1.9 metres, providing spaces for pause, reflection, and interpretation of the surrounding woodland and interesting facts about trees and timber.
The steel balustrade is strong and light, ensuring that the minimum materials were used to reduce the overall impact on the heritage landscape, with timber legs chosen to age naturally over time. The concept behind the design makes reference to the complexity and elegance behind the fundamental structures of the genetic code of trees.
Sophie Nash, Project Manager, Forestry Commission, said: “The walkway came from the idea to create a new visitor experience at the arboretum so we ran an architectural competition for designs. We had over 50 submissions from which we chose Glenn Howells Architects and BuroHappold design.
“The main challenges of the project were constructing an unusual structure whilst the arboretum remained open to the public. The walkway is over 300m in length and close to a number of trees, some of a significant size. Four cranes were required to lift each section of deck and legs over the top of the trees. The longest legs were 14 metres.
“It’s fantastic to make the RICS shortlist and it’s great to receive recognition for a project like this, which was funded by third party donations. We made sure that everything was built to a high standard and this is one of the most successful projects we have delivered.
“We have also received a number of other awards for the project including a 2016 Wood Award, a Civic Trust Award and it is shortlisted for many others. I am very proud of the scheme and it’s great to see people enjoying the walkway.”