Jewel Changi Airport: Forest Valley and glass dome

The idea of Jewel was first mentioned in Prime Minister Lee Hsien Loong's 2013 National Day Rally speech. The project was carried by a joint venture of Changi Airport Group and CapitaLand on the former open-air car park in front of Terminal 1, and construction began on 5 December 2014. Its cost is given as S$1.7 billion, whereas a Straits Times headline of December 2013 had announced S$1.47 billion. A consortium led by Moshe Safdie drew up the design, with RSP Architects Planners & Engineers as executive architects and structural engineers and PWP Landscape Architecture for the planting; ASLA notes that the team worked on it for six years.

Opening came in two stages: a soft opening on 17 April 2019, then the official opening on 18 October 2019 by the then Prime Minister. According to Wikipedia, the complex enlarged Terminal 1's arrival hall and baggage reclaim area by 70 per cent, and attendance reached 50 million visitors in six months, then more than 80 million in 2024. Safdie presents the whole as an echo of Singapore's image as a "city in a garden" and as a new building type pairing a marketplace with a garden.

The envelope is a toroidal gridshell of glass and steel: a covered ring whose geometry allows several levels and the neighbouring terminals to be linked. The façade engineers BuroHappold count more than 9,300 triangular glass panels, each one unique, and a mass of about 4,000 tonnes; Wikipedia speaks of more than 9,000 pieces of glass over a footprint of 200 by 150 m, but the BuroHappold page itself gives two sets of dimensions that do not agree. The central oculus is offset from the ring's centre to clear an existing airport train line, which makes the geometry slightly elliptical. Supports are kept to a minimum around the garden's perimeter, so the interior is almost column-free.

The Rain Vortex falls through the oculus, a 40 m waterfall according to the official site; in storms, recycled rainwater can flow through it at more than 10,000 gallons per minute, Safdie states. An acrylic funnel limits splashing and noise, according to Wikipedia. A displacement ventilation system provides comfort for visitors and plants. ASLA adds that air movement, humidity and natural light were balanced, the interior being slightly cooler and less humid than outdoors. The inter-terminal train runs through the gardens.

The official site announces more than 900 trees and palms and about 60,000 shrubs in the Forest Valley, an indoor garden lit by natural sunlight. Before opening, ASLA mentioned about 2,500 trees and 100,000 shrubs, and Wikipedia gives about 3,000 trees and 60,000 shrubs of 120 species. Wikipedia credits the Forest Valley with about 22,000 m² over five levels.

ASLA describes planted terraces, with planters faced in Indonesian lava stone that epiphytes can colonise, and names three trees: Terminalia (native to Madagascar), Agathis borneensis (Malaysia and Indonesia) and Agathis robusta (Australia), among about 200 mostly highland plant species. On the top level, the ticketed Canopy Park adds wide-spreading Ficus trees meant to give shade, a Topiary Walk and a Petal Garden.

The Forest Valley is the garden at the foot of the building, around the waterfall; according to the official site it is open every day, 24 hours, with entrances and exits between levels 1 and 4. Luggage and wheeled bags are not allowed inside (storage is available). Two trails climb gently to the Canopy Park on the top level: the eastern one passes rocky falls, the western one a mist; allow about half an hour per trail, with seating and several exits. The official site announces a light-and-music showcase on the waterfall in the evening.

The ticketed Canopy Park extends the visit with a glass-floored bridge, mazes and nets. Jewel is connected directly to Terminal 1 and, by pedestrian bridges, to Terminals 2 and 3. For another large glasshouse in the city, the Flower Dome and Cloud Forest of Gardens by the Bay lie about 16 km away as the crow flies.