Changi Airport's future Terminal 5 will be five-storey-high, 10 million sq ft. T5, slated to open in 10 years (mid 2020s), is expected to handle up to 50 million passengers a year. When completed, T5 is likely to be the third largest passenger terminal in the world, after facilities in Dubai and Beijing.
Changi will be able to handle up to 85 million by 2018, when T4 is ready and T1 is expanded. By the time T5 starts operating, Changi's annual capacity will hit 135 million passengers, with further expansion potential of another 20 million with satellite terminal, for a total of 155 million passengers capacity. The expansion also includes a 3rd runway.
Future of Changi Airport have a potential of 5 runway system
The existing land of Changi East allows up to four 4 km runway. The existing 2 runways are both 4 km each. The future reclamation plan allows yet another 3.3 km runway, which is sufficient for all commercial aircraft. The minimum runway length for A380 is 3 km.
Currently, Changi Airport is also studying the need for a fourth runway to cater to more flights in the coming decades, even as plans are finalised for a third landing and take-off strip.
Potential annual passenger handling capacity of Changi Airport is 250 million
As a rule of thumb, one runway can handle around 50 million passengers per year. A five runway system allows Changi Airport to handle 250 million passengers. By them, It would need at least two more terminals, on top of Terminal 5.
Hartsfield–Jackson Atlanta International Airport, the busiest airport today handles 100 million passengers annually. Changi handles around 55.4 million in 2015.
Singapore air traffic growth
For the past one two years, Changi Airport see stagnant growth in passenger traffic. This year, she register around 9% growth. For the past 10 years, she grows at around 5% annually. The 5% growth rate for the next 10 years will bring passenger traffic to 90 million in 2026 -- enough to justify T5 existence.
IATA forecasted that by 2035, Singapore airport will receive 117 million passengers.