New check-in counters, baggage belts, carpets and floor tiles are in place at Changi Airport's Terminal 1, where renovation work is 85 per cent complete.

Changi Airport Group (CAG) has provided an update on the $323 million upgrade, which began three years ago and is on course for completion by the middle of next year.

Overall floor space has also been expanded during the second round of major renovations at T1 in just a decade, as Changi Airport strives to stay ahead of rival airports in the region that are all gunning for a bigger slice of a growing air travel market.

T1's expansion has also added much-needed capacity, with the terminal now able to handle three million more passengers a year, taking Changi's total annual handling capacity across all four passenger terminals to 85 million.

The increase at T1 comes mainly from the addition of more self-service check-in kiosks and bag-drop machines that allow travellers to print their own luggage tags, according to CAG's T1 expansion programme management office general manager Su Chun Yang. There are now 50 self-service check-in kiosks at T1, with space set aside for another 42 to be added if needed, as well as 60 bag-drop machines.

Most of the remaining work is being carried out in the transit arrival area, where two more baggage belts are being added to the existing eight, which are being upgraded.

The baggage claim floor area is being almost doubled in size, and T1's baggage handling system has been fully automated - in line with the rest of the airport's terminals - so that check-in bags are sorted automatically.

CAG spokesman Ivan Tan said: "As demand for air travel in the region continues to grow, we are enhancing capacity in Changi's terminals to meet this growth. At the same time, we are taking the opportunity to introduce technology, such as Fast (a suite of self-service options), to continue to improve efficiency and optimise resources."

Travellers and visitors such as marketing executive Derek Tan, 38, are happy with the enhancements.

"I travel around the region a few times a month, and while many other airports tend to look dated after a while, Changi keeps upgrading and refreshing not just T1 but all its terminals every few years," he said.

Retired office manager Alan Goh, 67, said: "I don't necessarily like the hoardings that keep coming up, but to be fair, they are quite nice to look at, and whatever happens behind the walls, there is never any dust or sound, so that's good."

In 2012, Changi Airport completed a $500 million upgrade of T1 that focused mainly on the transit areas.

One key highlight in the public area was the construction of a kinetic rain sculpture with 1,216 bronze droplets that move constantly to create waves.