Editor's Note — This article was originally published in June 2015.
(CNN) — It already contains a butterfly garden, swimming pool and cinema, but for Changi airport in Singapore the sky appears to be the limit -- with new terminals and complexes in construction and planning for the next decade.
The airport has long set the precedent for others worldwide -- ranking No. 1 in the World Airport Awards for three consecutive years. With a current capacity of 66 million passengers a year, the opening of terminal 4 in 2017 will see this number rise to 82 million.
And it doesn't stop there. Developers want Changi to eventually handle at least 130 million people a year.
"We think we are sitting in a sweet spot in Changi," says Poh Li San, vice president of the Terminal 4 Program Management Office at Changi Airport Group. "We are looking at the growth of the whole region with China, India, and Indonesia growing rapidly," he says.
To compete with this growth, the airport needs to build capacity -- starting with terminal 4.
Tearing up the rule book
The elaborate retail space in terminal four will have cultural shop fronts in transit lounges.
"Sometimes you've got to tear up the book and relook at all your assumptions," says Stuart Ralls, senior manager of projects at Changi Airport Group, who believes the group need to veer away from trying not to rock the boat when thinking of new designs.
Innovative design has been the basis for terminal 4, but it comes with a price tag of more than $700 million.
With the goal of hundreds of millions of passengers passing through comfortably each year, the city-state's pockets are digging deep to ensure economic growth comes in parallel.
Build build build
The airport's newest project -- known as "jewel" -- is already in development and due to open in 2018.
The jewel at Changi airport will contain a 40m rain vortex falling from the roof surrounded by Singapore's largest indoor garden.
The large doughnut-shaped complex will be 10 stories high -- five underground and five above ground -- and add further extravagance to the airport grounds through an indoor forest with hiking trails and 40-meter rain vortex falling from the roof.
The forest will be the largest indoor garden in Singapore and the vortex will be crowned the world's tallest indoor waterfall with an accompanying sound and light show also planned. The complex is thus intended for use by both locals and travelers passing through.
Plans are already in development for a fifth terminal, while the group use terminal 4 as a test-bed.
The two-storey terminal 4 building will span almost 200 square meters and include a wide-range of self-service options including automated check-in, immigration and boarding. But some of these technologies are already in practice elsewhere in the world and airport developers have looked beyond Singapore's shores for their inspiration.
"In terms of self-service check-ins there are quite a number of airports that have provided a very good experience," says Josephine Teo, senior minister of state for Singapore's Ministry of Transport.
Teo recalls good check-in experiences at Kingsford Smith airport in Sydney. "That aspect of it is very well done," she says.
The airport is a source of national pride and its award-winning success is critical to the nation's economic growth -- acting as a gateway for Singapore to the rest of the world.