For three decades, the 75-year-old man and his wife had been living in a three-room flat in Ang Mo Kio.
But when she fell ill, part-time cleaner Lee Teck Seng downgraded his flat to pay the medical bills.
The couple have four children, but Mr Lee did not want to burden them.
He is now the owner of a 484 sq ft studio apartment in Hougang which he bought for just over $106,000 after selling his old flat for $370,000.
He moved in with his wife and a domestic helper last October.
"My children have their own families. I might also need the money in the long term," the former driver explained.
His wife died three months ago, and Mr Lee now lives alone.
His is one of 7,600 households that have downgraded to a studio apartment over the past eight years.
To date, HDB has offered about 11,200 of these units.
There are 49 developments with integrated studio apartments and 19 standalone ones, in various towns across the island.
Of these, 26 projects, with about 4,000 studio apartments, have been completed, an HDB spokesman said.
The scheme, started in 1998, was meant to be a housing option for the elderly, as well as a way for them to get cash from their flats. (See report above.)
But 16 years on, are these apartments, also known as granny flats, losing their appeal?
Property analyst Nicholas Mak noted this trend during last month's sale of balance flats exercise.
A little over a quarter, or 870 flats, offered during the exercise were studio apartments.
"Considering the limited supply of studio apartments (compared with other flat types), it shows that this type of flat is not very popular among its target buyers which are the elderly," said Mr Mak, SLP International Property Consultants' research executive director.