A surveyor on Tuesday said redeveloping Choi Hung Estate could save housing authorities hundreds of millions of dollars a year in maintenance, as well as allowing for an increase in the number of flats.

Sources say the Housing Authority has decided to redevelop the public estate, which is known for its open spaces and colourful design.

Vincent Ho, a former president of the Institute of Surveyors, told an RTHK radio programme that the complex, which is more than 60 years old, was likely to need a lot of costly repairs.

"For old housing estates, sometimes reinforcement work needs to be done because of peeling concrete and water seepage. The cost of repairs can be twice or three times the level for housing estates that are 20 or 30 years old. So it can cost HK$200 million or HK$300 million every year," he said.

Ho said 40- or 50-storey buildings can be built to accommodate more households as the redevelopment will not be subject to the height restrictions imposed at the estate due to the old Kai Tak Airport nearby.

FTU lawmaker Bill Tang said redeveloping Choi Hung Estate can also allow facilities like a community hall and a sports centre to be built in the area.

But the Kowloon East legislator told RTHK that he hopes officials will retain the rainbow-coloured exterior wall design in the new housing project.

"The Choi Hung basketball playground is very famous, so I also hope the new Choi Hung Estate can keep the original design," he said.

Secretary for Housing Winnie Ho, meanwhile, declined to confirm that the authorities are tearing down the estate to build new housing here.

"We are carefully choosing projects, to see if they are suitable. We consider a few aspects, including the quality of the building structure, the amount of money we're already using for repairs and maintenance and whether it will be more difficult to maintain the buildings as time passes, as well as whether there are places nearby to accommodate the residents," she told a Metro radio programme.