The practice was commissioned to design a mixed-use scheme above and around the new Canary Wharf Crossrail Station. Crossrail is the largest infrastructure project in Europe and will connect London from east to west, with nine new stations and 42 kilometres of new tunnels under the city. Located in the waters of the north dock next to the HSBC tower and close to the residential neighbourhood of Poplar, the development’s new public spaces are conceived as an accessible, welcoming bridge between the two areas. The four levels of retail, roof garden, pavilions and station entrances are unified by a complex timber roof, which wraps around the building like a shell.
The 310-metre-long roof arches 30 metres over the park and stretches around the shops and entrances below. The roof’s lattice opens in the centre to draw in light and rain for natural irrigation, and opens along the sides and at either end to allow views of the water and surrounding streets. Providing a warm, natural counterpoint to the steel and glass towers of CanaryWharf, the wooden structure evokes the ships that once sailed into West India Dock. The spruce glulam beams are sustainably sourced and support ETFE cushions, which are filled with air and lighter than glass. Where cushions are removed, the timber is protected by aluminium flashing. Further developing an approach pioneered in the flowing glass roof the Great Court at the BritishMuseum and Smithsonian Institution Courtyard, the design of the lattice is a fusion of architecture, engineering and sophisticated three-dimensional modelling. Remarkably, despite the smooth curve of the enclosure, there are only four curved timber beams in the whole structure. To seamlessly connect the straight beams, which rotate successively along the diagonals, the design team developed a system of steel nodes, which resolve the twist.
The roof garden is accessible from ground level via two connecting bridges, and bounded at each end by pavilions. The ETFE cushions, which are a highly insulating material, help to create a unique microclimate for the garden below, allowing the garden to be planted with some of the species that first entered Britain through the docks. When open at night, the building will glow, drawing visitors to use the public facilities and garden and creating a welcoming civic gateway to London’s growing commercial district.