Housing Board flat owners who downgrade to a studio apartment have net sales proceeds of around $200,000 each, after paying off the outstanding loan for their old flat and fully paying for the new one.

These former owners of three- or four-room flats form 70 per cent of the 7,600 households who booked studio apartments from 2006 to 2013, Minister for National Development Khaw Boon Wan said in a blog post on Wednesday.

Studio apartments, which can only be bought by those aged 55 and above, have elderly-friendly features such as grab bars and alert alarm systems. Two-thirds of those buying these flats were aged below 65, and half were living alone, noted Mr Khaw.

Studio apartments are "effective in helping seniors in their retirement. They are particularly attractive to seniors living alone, who will otherwise find maintaining a large flat a chore," he said.

But because so many live alone, they will need family and community support, he added. "Hence, we are determined to help families who want to stay near to each other realise their dream."

For instance, studio apartments are being included in integrated developments such as the upcoming Kampung Admiralty, which will also have a medical centre, childcare and eldercare centres, and shops. The apartments there will be launched in the July Build-to-Order exercise.

"We will continue to experiment and try out new layouts to see what will work best for our seniors, and to enable them to age actively where they live, in their familiar HDB town," said Mr Khaw. Now, only 22 per cent remain in the same HDB town when they move into a studio apartment.