A programme to upgrade hawker centres that began in 2001 has ended, having covered 106 such centres and undertaken at a cost of $420 million, Second Minister for the Environment and Water Resources Grace Fu said yesterday.

She told Ms Lee Bee Wah (Nee Soon GRC) that the views of stallholders are taken into account and upgrading is not carried out unnecessarily.

"The newest hawker centre that (underwent) an upgrading programme was actually one that was upgraded 24 years after it was built," she said.

"So I don't think that's an unreasonable length of time to have a major upgrading. We don't upgrade a centre unnecessarily. We determine only what is required to basically improve the experience of the patrons."

Ms Lee said there had been feedback from residents about price increases after hawker centres were refurbished or upgraded, and some even asked if improvement works were necessary.

Ms Fu said hawker centres are not upgraded more than once.

Subsidised hawkers of cooked food pay a monthly rent of $192 after standard upgrading, while those at centres that underwent major works pay $320 a month.

While she did not state the pre-upgrading rent for subsidised hawkers yesterday, this has been reported as being $160 a month.

For other non-subsidised stallholders, rents are adjusted based on professional valuation, Ms Fu said, adding that the Government does not recover the full cost of upgrading.

As for Ms Lee's query on subletting of stalls, Ms Fu said the National Environment Agency has disallowed subletting by new stallholders since April 2012.

Existing stallholders had a three-year grace period, ending March next year, to comply. After that, all stallholders need to operate their stalls themselves.

WALTER SIM