Lift company Sigma Elevator was still banned from tendering for new projects, the Housing Board said last month, as its performance has yet to meet the required standards.

This was nearly a year after the HDB said it had forbidden Sigma from bidding for new projects since October 2015.

This is so that the firm could "focus on improving the installed lifts under its current contract".

There are around 3,500 lifts built by Sigma out of about 24,000 lifts in HDB estates.

Last year, HDB noticed a higher-than-usual breakdown rate in lifts installed by Sigma in their first year of operation. An investigation found that the doors and sensors were more prone to misalignment, possibly due to knocks from rough usage because of renovation and home-moving activities.

As of this month, residents at various new HDB estates with Sigma lifts say they still have not seen much improvement, with some experiencing jerky lift movements and unresponsive lift controls.