Xstrata Walkway, Royal Botanic Gardens Kew

The 18m high, 190m long treetop walkway in Kew Gardens is an example of the complete integration of an architectural idea with an elegant and efficient structure. We suggested the use of weathering steel as a material whose colour would blend well with nature, yet would look man-made, and that would not need painting in the future.  

It was a challenge to design and construct the walkway and its foundations without damaging the trees or their roots.  We worked closely with the head arboriculturist and the steel fabricator and designed innovative steel grillages instead of concrete pilecaps.  We worked with wind engineering specialist RWDI Anemos to apply wind spectra to our dynamic analysis model to determine the accelerations that would be felt at different wind speeds and hence define limits for both comfort and safety.

Structural engineering by Jane Wernick Associates, now part of engineersHRW.