On top of regulating the private market, the government could help make the subsidised flat market more liquid while ring-fencing it for local residential use. It should offer more subsidised flats for sale and also start building bigger homes.
If the government wants to eradicate subdivided units, increasing public rental housing supply alone will not get the job done. Too many people are ineligible to rent government-subsidised flats, and maintaining these estates comes at a steep price.