The last of Singapore's 18 HUDC estates, Braddell View, has been designated for privatisation, said the Ministry of National Development on Tuesday.

But before the privatisation works can begin, land lease issues must be sorted out. The estate, comprising 918 flats and two shops, was developed in two phases on two separate land leases, with different expiry dates.

To harmonise these leases - such that they have the same expiry date - the land lease of the older land parcel will be "topped-up" to that of the newer one. A land premium must thus be paid by every flat owner in the estate.

Residents will vote on whether to privatise the estate. If the required mandate of at least 75 per cent in favour of the move is obtained, the amount of top-up premium will be determined by the Chief Valuer Office and the Housing Board will apply to the Singapore Land Authority for the top-up.

"After the lease top-up, the whole process of legal privatisation can be expected to take about 15 months, barring any unforeseen circumstances," said the MND.

The first batch of Housing and Urban Development Company (HUDC) estates was built in the 1970s to help middle-income families own their homes. But by the 1980s, demand for them had dwindled due to more resale flats and affordable alternatives being available.

In 1987, HDB stopped building HUDC estates, and in 1995, it began privatising them.

Of the other 17 HUDC estates, 13 have been successfully privatised while the other four are in various stages of the process. These are in Hougang Avenue 2 and 7, Potong Pasir Avenue 1, and Serangoon North Avenue 1.

"The era of HUDCs has ended. However, HUDC estates will remain a testament to the creative ways in which we have housed our people and help them fulfil their dreams," Minister for National Development Khaw Boon Wan said on the Ministry's blog on Tuesday.