In the face of sustained demand, construction companies have been encouraged to scale up, leveraging on advancement in technology. The BCA has pushed for industry adoption of Building Information Modelling (BIM) and pre-fabricated pre-finished volumetric construction (PPVC).
BIM is a 3D digital visualisation tool that manages data from design to construction. Through the use of BIM by architects, engineers and contractors, designs can be analysed and potential design clashes resolved before construction begins. Rework during construction can be minimised, resulting in saving in time and costs.
The adoption of PPVC can bring about a quantum leap in productivity. By building homes, hostels, hospitals and hotels lego like, with panel walls, entire rooms and bathrooms made in factories in Singapore, Malaysia or China, companies can reduce the use of manpower and machinery and slice the time taken for completion.
The government is driving change in the industry. Speaking at the BCA-REDAS Built Environment and Property Prospects Seminar 2016, Desmond Lee, Senior Minister of State in the Ministry of Home Affairs and Ministry of National Development, said, “Public sector projects will account for more than half of the construction demand in the next few years. So the public sector will take the lead in transforming the way we build in Singapore. We will plan for productivity improvements in our projects, emphasise the role of Design for Manufacturing and Assembly (DfMA), and adopt impactful technologies or processes where it is feasible.”
To create a strong lead demand for the adoption of DfMA, selected sites under the Government Land Sales programmes are required to adopt PPVC. The BCA will also incorporate more DfMA principles in the buildability framework.
Crowne Plaza Takes the Lead
The extension of Crowne Plaza Changi Airport Hotel by OUE Limited, the first private sector commercial building to be completed using the PPVC method, provides a graphic example of what can be achieved with the adoption of smart solutions.
The 243 new rooms completed with finishes, fixtures and fittings were fabricated in Shanghai before they were shipped to Singapore to be assembled on site. As an average of 10 PPVC modules were assembled per day, it took just three or four days to construct a floor, compared with 14 to 21 days using conventional construction methods. Although changes to the room designs had led to delays, the project could still be completed more quickly, as it would take only four months using PPVC, instead of 12 months, for on-site works.
Transporting all the units using PPVC required only 300 vehicle trips, compared to 1,250 trips for conventional building construction projects. As less of the work was done on-site, the number of workers employed could also be smaller – 36 against 60.
The PPVC method helped to boost the project’s overall productivity by about 45%.
The BCA’s chief executive Dr John Keung said that the project served as an example of what the PPVC method can achieve. “We hope we can build up the expertise here, whether it’s architects or contractors or developers, to give this technology a big push.”
Costing S$82 million, the 10-storey extension was completed in June 2016, adding significant capacity to the existing 320-room hotel.
Cost can be an issue in the adoption, as PPVC can cost about 18% higher than conventional methods. In the Crowne Plaza extension, this was largely due to the high cost of shipping the prefabricated modules from Shanghai. As the technology is relatively new to Singapore, the learning curve is also steep.
These issues are being addressed. Cost will also dip with increased adoption.
Speaking during a Crowne Plaza worksite visit in February 2016, National Development Minister Lawrence Wong said: “With greater adoption of PPVC and new technologies, the cost differential will come down...the premium is due to prototyping, but with more repetitive adoption, with greater economies of scale, the cost will come down and technologies like PPVC will eventually become very economic, even without the grants. So we see the grants as a temporary measure in order to kick-start the industry to catalyse adoption.”
The BCA offers grants to incentivise adoption. In late 2014, an extra S$55 million was injected into the Construction Productivity and Capability Fund, which helps firms adopt new technology and develop their workforce. That brings the total amount of productivity funding set aside for the construction sector to S$335 million.
To build local off-site manufacturing capacity and capability, the BCA will launch more integrated construction and precast hubs (ICPHs) in 2016. Unique to Singapore, the ICPH is a highly automated, multi-storey factory for producing precast concrete building elements such as staircases as well as volumetric modules such as bathrooms.
Productivity Guidelines for Tunnel Builders
Modular construction is being extended to civil engineering projects in BCA’s drive to raise productivity within the industry. The BCA is planning to expand the existing ‘buildability appraisal framework’ to tunnelling projects, which will form a larger proportion of total construction demand in the next few years. Designers and developers are encouraged to consider labour-saving designs for tunnelling projects, adopt more mechanisation and prefabrication components and to reduce the amount of excavation and concreting.
This will improve labour productivity and cause fewer disruptions to adjacent environment. It will also be a boon for productivity as Dr Keung noted, “Take MRT projects – in terms of productivity, they are actually better than building projects because when you do tunnelling, you need to use a lot of advanced equipment, machines and so on.
“But there are many other kinds of things you can do, like the tunnel lining for example. When you have a tunnel, you line it. We can do it in a more efficient way with prefab and precast. So the whole idea is similar, in which you can do as much work as possible off-site in a factory and bring them on-site for installation.”