Ageing public housing towns will remain liveable as the Housing Board begins choosing a second batch of flats for upgrading works in 2020.

These Home Improvement Programme (HIP) flats will come from among the 230,000 homes built between 1987 and 1997, Minister for National Development Lawrence Wong said yesterday.

Town councils will be invited to nominate their flats later this year, he told Ms Lee Bee Wah (Nee Soon GRC), who had asked for a timeline.

It is hard to say when the upgrading works for all these flats will be completed as it depends on the availability of funds, he said. "We can't commit to a schedule today, but if you look at the previous round... it took about 13 years."

The expansion of the HIP was announced by Prime Minister Lee Hsien Loong during his National Day Rally speech in August 2018.

The programme covers fully-subsidised, essential items like spalling concrete and the replacement of waste pipes, as well as optional and highly-subsidised ones like bathroom upgrading.

It will cost the authorities a total of more than $4 billion.

He said the authorities will give updates on HIP II - a second round of upgrading for flats between 60 and 70 years old - and the Voluntary Early Redevelopment Scheme (Vers), which gives owners of ageing HDB flats a chance to sell their homes to the Government.

Mr Wong also said remaining flats under the first batch of HIP - those built up to 1986 - will be announced by the end of this year.

He told Ms Lee he would look into some of her suggestions to improve estates, like using funds to build designated smoking points and having smoke-free Build-to-Order flats.

Private estates will also be spruced up as the authorities select neighbourhoods for the Estate Upgrading Programme by the second half of 2019, he added.