Future residents of planned light public housing won't want to keep moving from one part of the city to another, the Federation of Trade Unions (FTU) said on Sunday.

The government plans to build around 30,000 such units by 2027 for people who have spent years on the waiting list for a public flat.

Several sites across the territory have already been identified for the homes, which are only designed to be temporary.

But FTU lawmaker Bill Tang said some people living in sub-divided flats have been surprised to learn that if they accept one of the new homes they could have to move to a new area, and then relocate again once they get hold of a traditional public unit.

Those with children are particularly concerned about moving repeatedly, Tang said.

He suggested that the government should give priority for light public housing to families in sub-divided units and to resettle them in the same district once a normal public flat becomes available.

Tang said the FTU held talks with officials in June about the possibility of establishing a registry of sub-divided flat occupants to help identify families with children.

He said although the government didn’t directly accept the proposal, it did agree with the idea of prioritising families with children when formulating policies related to sub-divided flats.