Kew Tree Top Walkway

The 200m long treetop walkway at Kew Gardens takes visitors up 18m high to experience the forest canopy.

Our aim was to design the walkway to be a visually light, discreet presence, at ease in its natural surroundings; while at the same time being unashamedly man-made. We decided to integrate the main truss structure with the handrail support and drew for its design, on the Fibonacci sequence, which underlies many growth patterns in nature. The progressive number sequence results in a higher density of elements near the truss-ends where the vertical loads are highest. An early decision to use beautiful, low maintenance weathering steel, led to the design of the tapered, triangular pylons and their trifurcated node supports, as this steel is only manufactured in flats.

A major challenge was to enable visitors to get as close as possible to the tree canopies without damaging the complex tree root system below ground. A radar survey was undertaken to understand the extent of tree root activity at each pylon location. This enabled us to strategically position the 12-18m long concrete piles between the major roots and led to each pile cap being bespoke.

Awards: RIBA Award 2009; Structural Steel Award 2009; Civic Trust Award 2009; ICE Structural Award 2009; FX Award – Leisure and Entertainment sector 2008; Conde Nast Travel Awards 2008; The Observer People’s Choice Awards 2008