Housing minister Winnie Ho said on Saturday the Rating and Valuation Department has received two complaints of landlords forcing tenants of subdivided units to move out so they can be renovated to meet government requirements.

In his policy address in October, Chief Executive John Lee outlined plans to replace substandard subdivided units with so-called "basic housing units". These must be no less than 8 square metres, or 86 square feet, and have an individual toilet and at least one window.

Speaking on an RTHK programme, Ho said tenants' rights are protected under the law.

"Tenant's security of tenure is protected. The tenancy contract is regulated for two years plus an additional two years. If water and electricity bills are separate, landlords are not allowed to overcharge for them. The tenant's fees for these services cannot be higher than the service charges that the landlord pays to water and electricity companies," she said.

Ho stressed that the basic housing unit policy is still under consultation, and further adjustments may be made before the bill is tabled at the Legislative Council.

Separately, Ho said the decision to have the South Island Line (West) adopt the smart transit system cut six years from the construction time, allowing the government to advance the redevelopment of Wah Fu public housing estate.

The government announced on Friday that the estate's last remaining residents now have to leave by 2034/35, six years ahead of schedule.

"Yesterday the transport chief announced that the railway will use the Smart and Green Mass Transit System, rather than an underground heavy rail system. The green system, which runs above ground, will save almost six years," Ho said.

"We originally set aside land in the estate for an underground station... and could only move residents after the station was built. But now that land is freed up, and we can put up buildings immediately, speeding up the redevelopment," she added.

The government announcement also laid out clearance and rehousing arrangements for the first phase of the redevelopment of Choi Hung Estate. Residents of Pik Hoi House, Kam Pik House and Tan Fung House will need to move out before April 2029.

Ho said redevelopment decisions are made according to the condition of the estate and its urgency.

She added that the government is yet to discuss building heights, plot ratios and road networks of the redeveloped Choi Hung estate.