From 2019, all the rooms in one-third of new HDB flats launched will be pre-fabricated as a whole - as part of a government push that is set to shorten construction time and lower costs in the long run.
Entire rooms will be constructed in factories before being assembled on-site. They will come with finishes such as floor tiles, window frames, flooring and a lick of paint.
All newly launched projects will also have pre-fabricated bathrooms with copper piping, partial tiling and a waterproofing system.
The quality will also improve, compared with previous pre-fabrication efforts, said the HDB.
The construction time for Build-To-Order (BTO) projects is currently around three years, but an HDB spokesman told The Straits Times this might shorten as contractors become familiar with Pre-fabricated Pre-finished Volumetric Construction (PPVC).
The method will reduce the manpower needed in the construction industry, long reliant on foreign workers, said HDB. Installing PPVC rooms and bathrooms will improve project productivity by 50 per cent and 10 per cent respectively, it said.
It is part of HDB's drive to boost its productivity by 25 per cent in 2020, compared with 2010 levels.
Number of pre-fabricated concrete bathrooms installed in 15 projects by HDB.
Percentage of flats launched this year that will feature these pre-fabricated bathrooms.
Speaking at the annual HDB Awards last night, Second Minister for National Development Desmond Lee said the agency is on track to meeting the goal. "HDB can construct a four-room flat in 182 man-days today, compared to 205 man-days in 2010," he said.
In the short run, though, the industry has to grapple with investing in costly technology. An HDB spokesman said initial construction costs will be higher - a 1 per cent hike for the pre-fabricated bathrooms and 8 per cent for the PPVC rooms per project. But she said these are not likely to have an impact on flat prices, as the HDB "takes into account the location, design features, individual flat attributes and prevailing market conditions".
But in the long run, said property analyst Ku Swee Yong, chief executive of International Property Advisor, flat prices should come down as construction firms "reap the benefits of economies of scale, reduced interest expenses and risk".
The PPVC method was piloted in Valley Spring @ Yishun, where construction for the 824 units started in March this year.
The pre-fabricated concrete bathrooms were piloted in Fernvale Lea, a BTO in Sengkang ready last January. The HDB has since installed 14,000 such bathrooms in 15 projects. It will install these bathrooms in 60 per cent of the flats launched this year, before rolling them out to all new ones in 2019.
Some are unsure about the new technology. Housewife Dion Lim, 38, said she was unhappy with the bathrooms in her Fernvale Lea flat. Her problems included uneven tiles, loose fittings and rusty doors.
But quality will be better, said the HDB yesterday. The units, built and monitored in a controlled factory environment, are supposed to be more uniform and of better workmanship.