Towards the end of 2014, the International Air Transport Association released its first 20-year passenger growth forecast which estimated air passenger numbers would reach 7.3 billion in 2034. This means that more than double the number of passengers that fly today will be rushing through crowded airports in twenty years' time.
While airports must ensure that the basic infrastructure is there to support this level of increase, they also have to implement more sustainable building environments and incorporate natural green spaces to meet passengers' changing criteria for satisfaction. It has long been proven that green public spaces have restorative powers and more and more airports are now providing areas that allow passengers some time out in more natural surroundings.
"The densification of cities and the increasing scale of public realm development such as airports and malls, often deprived of daylight and any contact with nature, has brought about a reaction: a craving for nature, daylight, greenery," says Moshe Safdie, architect and founder of Safdie Architects. "A similar evolution is occurring in the work space, where mega office buildings have now begun evolving towards smaller footprints and the incorporation of gardens and atria for relief."
Changi Airport's gardens
Safdie and his team are the design inspiration behind Jewel, the new addition to Singapore Changi Airport: a $1.2bn glass dome stretching over 134,000 square metres, integrating nature, leisure activities and airport facilities.
Up until now Changi Airport - winner of Best Airport at the World Airport Awards in 2014 - has been one of the leading examples of how natural amenities can be integrated into airport spaces for the benefit of passengers. In Terminal 3 the Butterfly Garden includes around a thousand tropical butterflies of 40 different species, lush foliage and a six-metre waterfall.
The airport uniquely encourages passengers to go on a nature trail through: Terminal 1's Cactus Garden, where passengers can "stretch out and bask in the sun"; Terminal 2's Sunflower Garden, where passengers can view the runway surrounded by 500 flowers; and the Orchid Garden, which features more than 30 species of orchid.
Forest Valley at Changi's new Jewel dome
The new Jewel development, which will be positioned at the centre of Changi Airport, is designed to establish a new model for airports as destinations, boost Singapore's appeal as a stopover location and offer high-level facilities that will help passengers to relax.
The glass dome, which is scheduled for completion in 2018, is home to a hotel, restaurants and shops. But its two centrepieces are naturalistic: Forest Valley, comprising trees, ferns and trails; and Rain Vortex, a 40m waterfall.
"Many passengers at Changi are on long trips across the globe, stopping over for a few hours as they change planes," says Safdie. "The opportunity to be in a great pleasure garden, which also incorporates educational and fun attractions for the citizenry at large, seemed the appropriate response."
Wishing for the design to be timeless and to celebrate Singapore's identity as the "city in a garden", Safdie describes the Jewel as one of the "great landscape indoor spaces in the world as part of the airport experience".
South Korea's Incheon Airport
Also keen to establish a new benchmark for airports is Gensler, as the collaborating design architect with the HMGY (Heerim-Mooyoung-Gensler-Yungdo) Consortium for Incheon Airport's Terminal 2 design. Ranked best in the world for the last eight years by the Airports Council International, Incheon receives around 45 million passengers a year and the IATA predicts that the Asia-Pacific area has a growth rate of 4.9% and will see an extra 1.8 billion annual passengers by 2034, for an overall market size of 2.9 billion.
The new $2.5bn terminal will accommodate the increasing passenger traffic by doubling the airport's size and mixing retail facilities with vast areas of green space, koi ponds, streams and waterfalls.
"It's a large international terminal, yet it will be very intuitive to navigate and present unique experiences like the vast interior gardens featuring native Korean foliage," says Keith Thompson, leader of Gensler's global aviation design practice.
According to Gensler there are acres of plantings in the new 72-gate terminal, which will enable it to be more energy efficient as they will help to lighten air-conditioning and ventilation loads, and two main gardens that reflect the flora and art of Korea. Other sustainable design features include photovoltaic cells that use the sun's energy to light up interiors in co-ordination with the skylights - which also helps to produce a dappled sunlight effect in the building.
Rooftop garden and potato farm at JFK
Gensler also designed JFK Airport's Terminal 5 building and extension, in 2008 and 2014 respectively, as well as the new post-security rooftop garden which was opened by JetBlue on 1 July 2015. It includes a 375 square metre park, landscaped spaces and enough seating for 50 people.
The area also includes a 35 square metre dog walk area, a wooden roof deck, outdoor furniture and a variety of plants, such as oakleaf hydraneas, lilyturf and sweetsphire.
Design elements that emanate the look and feel of New York life have been incorporated for passenger fulfilment. "As rooftop bars, sunbathing and summer enjoyment are such a big part of living in New York City, we wanted to bring this unique aspect to customers travelling through T5," says Jamie Perry, vice president for brand and product development at JetBlue.
In October a 24,000 square foot blue potato farm and vegetable garden was opened to draw attention to local farmers and as an agricultural and educational resource for the community. It includes 3,000 crates of potato plants to harvest around 500kg of blue potatoes and 2,000 herbs and plants. The produce will be used in some of the restaurants in T5 as a bid for greater self-sufficiency - it also composts some of the food waste from outlets - and some of the yield will also be donated to food banks.
"Our customers expect T5 to offer them unique experiences," says Sophia Mendelsohn, head of sustainability at JetBlue. "We know from our T5 rooftop that people are drawn to light and green spaces, and they also have an inherent interest in understanding where their food comes from."
Chicago O'Hare Airport's aeroponic garden
Another airport with an interest in growing herbs as a way to provide customers with green surroundings is Chicago O'Hare Airport, which installed the first airport aeroponic garden in Terminal 3's Rotunda building. This garden does not grow plants with soil, but instead pumps a nutrient solution around its 26 towers and 1,100 planting spots in a self-sustaining process.
Some of the produce grown here, such as purple basil, thyme, oregano and green beans, is used at the restaurants and passengers are able to view the garden while eating in the lounge area.
The airport also features 30,000 square metres of green roofs in twelve locations and has a vertical GSky green wall in Terminal 3, which contains 440 plants in a 100 square foot space, improving air quality.
The beginning of a process
As passenger traffic increases so does the pressure to make airports greener, sustainable and more appealing to travellers. The gradual emergence of destination airports, such as Changi, are integrating natural green spaces with leisure and entertainment facilities, proving that an offering of restaurants, shops and WiFi in a traditional terminal building are no longer enough. Passengers need more to be satisfied and are positively responding to sustainable responsible environments, green surroundings and natural daylight.
Safdie believes that this is just the start. "I believe that this is the beginning of a process," he says. "We will see a greater emphasis on connecting to nature in the public realm generally, and in commercial urban spaces particularly."