Client Royal Botanic Gardens, Kew, London, UK
Architect John Pawson Architects
M&E engineers AECOM
Lighting design Speirs + Major
acdc products Q
Structural Engineer & Project Management Buro Happold
Electrical Engineer Atelier Ten
Cost Consultant Jackson Cole
Main Contractor Balfour Beatty
Electrical Contractor Pococks
The award winning lighting of the Sackler Crossing at the Royal Botanic Gardens, Kew enhances the experience of this elegantly designed structure after dark. The S shaped bridge designed by John Pawson Architects floats just above the surface of the lake playing with solidity and transparency. Constructed on a concealed steel frame the deck consists of 100mm granite planks with 30mm solid bronze cantilevered vertical uprights providing the balustrade. The gentle S shape allows the crossing to have many facets from giving it the appearance of it being solid and then transparent when viewed from on the bridge or when viewed from afar. The bridge reflects in the water of the lake, but also the water is reflected in the bronze of the uprights. The appearance of the bridge constantly changes.
The lighting was sensitively handled in relation to the context of the gardens. As the Royal Botanic Gardens remains mainly dark at night, the bridge softly shimmers in the darkness giving a moonlit effect and reflects in the water of the lake. The crossing was not seen in isolation with low level floodlighting to specimen trees on the adjacent island creating visual interest and focal point in the landscape allowing the bridge context after dark.
LED Design Solution Over 1000 discreet custom high output white LED fittings are recessed in the granite planks of the bridge deck at either side, between each bronze upright gently washing light up their inner surfaces. The fittings were developed with the light emitting diodes set low down in the fitting to minimise the visibility of the light source and an additional frosted glass front top plate eliminates any bezel being seen. The fitting has very clean and crisp appearance that complements the minimal design of John Pawson.
The LED uplights were developed with electrical wiring loom and plug and socket arrangement to aid the installation eliminating the need to wire each fitting. The final specification of the fitting was confirmed after prototyping both the fitting and installation method with careful consideration taken over the selection of LEDs in regard to colour appearance and the finish of the additional glass front top plate.