Prefabricated construction is gaining fans across the world. With walls, floors, bathrooms and even whole units complete with internal finishes, fixtures and fittings built in plants off-site, projects can be completed more quickly and efficiently with less noise and dust. Used since the Second World War in the United Kingdom to replace bombed-out homes, prefabricated units are now being incorporated in residential homes, hostels, hotels and even multi-user facilities, multiple storeys high.
The BCA is pushing for the adoption of prefabricated building technologies in Singapore to raise productivity in an industry which until now has performed below its peers in the United Kingdom, France, the United States and Australia. The high work volume is forcing the pace.
Speaking at the BCA-REDAS Built Environment and Property Prospects Seminar 2014, Senior Minister of State Lee Yi Shyan emphasised, “(The) built environment sector must ride on this strong growth, and restructure itself to be more productive. If the word, restructure, is not impactful enough, maybe we should say transform itself. This is an opportunity for transformation. We must all work hard to realise our vision for the built environment sector, namely, to transform it into a highly integrated, technologically advanced sector led by progressive firms, and supported by a skilled and competent workforce.”
Not only has the volume of work doubled over the last 10 years, expectations are higher. While the types of buildings and projects, whether public or private, are increasing in complexity, the time allocated for completion is becoming shorter. As BCA’s Dr John Keung told The Straits Times, “Today, we are building the Sports Hub – many times the size and complexity of The Esplanade – at a fraction of time it took 10 years ago.”
Under the revised Buildability Framework, which came into effect in September 2014, developers are required to:
• Adopt standardised floor heights and building components such as precast staircases, precast refuse chutes and doors in new projects; and
• Use drywalls as internal partitions for dry areas in all residential non-landed developments.
This will help downstream construction to achieve better site productivity and quality standards.
As developers have a greater role to play in driving construction productivity by setting the direction in adopting productive technologies, the BCA has mandated the use of Prefabricated Bathroom Units (or PBUs) for all residential Government Land Sale (GLS) sites as well as set a minimum percentage of prefabrication level for Industrial Government Land Sale (IGLS) projects.
Bathrooms are targeted for good reasons as bathroom construction is messy involving easily 13 different trades in a small confined space. By using PBUs, companies can cut down their manpower requirements for building bathrooms by 60%. More than 14,000 of such bathrooms have been installed in private residential projects since 2005, notes the BCA.
The adoption of prefabricated prefinished volumetric construction (PPVC) and cross-laminated timber (CLT) will also be required for some suitable GLS sites. In addition, a minimum percentage of prefabrication level will be set for IGLS projects. To encourage private developers to adopt new productive technologies, incentives will be given to those on non-GLS projects and those who are going beyond the requirements for GLS projects.
“Buildings can be completed faster with the use of these productive technologies. When pushing for the adoption of productive technologies such as drywalls, PBUs, PPVC and CLT, we look beyond just labour efficiency. We also consider if they can help to reduce dis-amenities to residents living near the construction site. As these technologies involve a large extent of off-site production before they are assembled on-site, we can expect less noise and dust during construction,” said Dr Keung.
To ensure that developers take greater ownership in implementing buildable design and use of labour-efficient construction methods, appropriate enforcement action may be taken against developers whose projects deviate from the approved plan while progressive firms with good track records will gain a higher productivity weightage under the tender evaluation framework.
Said Dr Keung, “Give us a few more years and everything will be built off-site for better quality control and for the construction site to become more of an assembly point with minimal noise, dust and much less impact on existing residents in a neighbourhood.”