Kew Gardens Irrigation Pump House

Hidden in a mound below one of the garden’s most iconic attractions, the Treetop Walkway, a buried tank stores 280,000 litres of irrigation water. The new pump house is perched directly above this tank to ensure the irrigation network has a constant reliable ‘heartbeat’. In the future, by adding harvested rainwater, Kew’s gardeners will massively reduce their reliance on mains water, preserving precious resources whilst also setting a new standard for environmental stewardship in horticulture. As the pump house is in full-view within the UNESCO World Heritage Site, the project sought to revive a grand tradition of marrying innovative engineering and decorative architecture within the gardens. This approach has its roots in the numerous small infrastructures and follies designed by Sir William Chambers and John Smeaton in the 18th Century. The expressive architectural enclosure draws upon this heritage and was conceived by Hugh Broughton Architects working closely with Kew stakeholders. Inspiration came from immersion within Kew’s living collections and from their archive of botanical illustrations. A design was developed which uses filigree visual screens made from interlocking European Larch struts arrayed into an oval-shaped plan. Dozens of sketch studies were made to mimic leaf structures, seed pods and palm fronds with 3D digital modelling used to analyse the sculptural design. The timber elements are detailed and specified to age naturally to a silver colour and to play with the dappled light and shadows of surrounding trees, so the resulting architecture will both complement the landscape and camouflage the inner workings of the infrastructure.