A jumbo HDB flat in Telok Blangah made headlines after it was listed for $2.18 million, prompting HDB to review the scheme that allows eligible owners to buy an adjoining flat and join the two into one larger home. But these flats are rare, raising the question of whether one unusual case is enough to warrant changing the rules.

On Viewpoint, Lynlee Foo speaks with Lee Sze Teck, Senior Director of Data Analytics at Huttons Asia, about why families use the scheme, how such unusual homes should be valued, whether renting out part of a combined flat goes against its original purpose, and what HDB should consider as it reviews the rules.