Summary- Reader Response Draft 2

Description: Prefabricated Prefinished Volumetric Construction

In the article “Design for Manufacturing and Assembly (DfMA)” published by Building Construction Authority (BCA) (n.d), it stated that Prefabricated Prefinished Volumetric Construction (PPVC) is one of the DfMA technologies. DfMA is a key pillar of Singapore’s Construction Industry Transformation Map (ITM). It is a game-changing method of construction which involves construction being designed for manufacturing off-site in a controlled environment before being assembled on-site. According to the website “Prefabricated Prefinished Volumetric Construction” published by BCA (n.d), it is a construction method whereby free-standing 3-dimensional modules are completed with internal finishes, fixtures and fittings in an off-site fabrication facility before it is delivered and installed on-site. By planning more works offside, manpower and time needed to construct buildings are reduced while ensuring work sites are safe, conducive and minimal impact on the surrounding living environment, according to the guidebook “Design for Manufacturing and Assembly (DfMA) - Prefabricated Prefinished Volumetric Construction” by BCA (2017). According to Chiang et al., (2006), with its numerous benefits, off-site construction has been highly recognised by global construction community and widely used by the construction industries in many countries and regions such as Hong Kong (Chiang et al.,2006) and Spain (Pons & Wadel, 2011).

PPVC presents a game-changing approach that not only addresses conventional construction challenges but also emerges as a pivotal force in shaping the future of sustainable and resilient urban development.

Adopting PPVC offers efficiency in accordance with BCA (n.d) guidebook, fabrication of PPVC can proceed in parallel in the factory while other worksite activities are ongoing to streamline the construction process. The on-site construction activities can be significantly reduced through the use of PPVC. It can potentially achieve a productivity improvement of more than 40% in terms of manpower on site and more than 20% time savings depending on the complexity of the projects. Unlike conventional construction methods that are often executed in a consecutive manner, PPVC allows works to proceed concurrently. Therefore, it can reduce the construction schedule significantly. Thus, it can expedite the project implementation significantly and thereby increase productivity. Furthermore, PPVC can bring tangible cost savings through a reduction in on-site manpower and equipment requirement when compared to conventional construction methods.

Secondly, PPVC provides sustainability which offers significant benefits over traditional onsite construction such as faster and safer manufacturing, better quality control and lower environmental impacts, thereby leading to sustainability benefits in terms of material efficiency, reduced onsite waste (up to 90%) and improved working conditions by Thai et al. (2020). The use of PPVC can reduce construction time by 50% and save cost by 20% based on a case study of recent projects by Thai et al. (2020). As more activities are done off-site, a reduction of environment pollution can be ensured as dust and noise pollution are potentially minimised. Disamenities to the surrounding neighbourhoods during construction can be diminished. Prefabrication of the building modules also leads to cleaner worksites by generating less overall construction waste on-site BCA (n.d).

 

Lastly, PPVC allows innovation in shaping resilient urban development. With accordance from Thai et al. (2020), the Australian construction industry is now experiencing rapid growth in modular construction. This is evidenced by the fact that four out of ten of the world’s tallest modular buildings were constructed in Australia in the last five years, Thai et al. (2020). Notable among them is Collins House in Melbourne which currently sets a new record as the world’s tallest modular building with 60 storeys. In recent years, the Singapore government has expended great efforts to encourage the use of modular construction for residential housing projects. Since 2014, it has been mandatory to use modular construction in public residential buildings. A series of guidebooks on DfMA technologies were also recently published by BCA of Singapore to provide practical guidance to practitioners on how modular buildings could be designed, fabricated and assembled to achieve the full benefits of DfMA methods. In addition, the Singapore government also provided significant financial assistance to support Singapore’s construction industry in moving towards the adoption of DfMA to enhance quality and productivity. A list of current modular construction projects in Singapore is reported, which indicated that most of current modular buildings were constructed up to 20 storeys high. Only one project completed recently (Clement Canopy Tower) was constructed up to 40 storeys and became the tallest modular building in Singapore. This tower set a new record for the world tallest concrete building constructed using PPVC method. The Clement Canopy tower is also one of the world’s tallest modular buildings. The Clement Canopy project comprising twin towers with 505 residential units was constructed from 1,899 prefabricated prefinished volumetric concrete modules with 48 different module shapes using the core-based method. Each module was prefabricated in an off-site factory with approximately 85% finishes for walls, floors, ceilings and MEP systems before being transported to the construction site and attached to the concrete core using wet joints. This project demonstrated the benefits of using the PPVC method in terms of saving construction time (30%) and reducing environmental impact (up to 70% onsite waste 30% off-site waste) by Thai et al. (2020).

 

To summarise, PPVC is a transformative method offering solutions to traditional construction hurdles while significantly contributing to the advancement of sustainable and resilient urban development. Its innovative approach marks a crucial shift in the construction industry towards a more efficient and environmentally conscious future.

References

Chiang, Y.-H., Hon-Wan Chan, E., & Ka-Leung Lok, L. (2006). Prefabrication and barriers to entry—a case study of public housing and institutional buildings in Hong Kong. Habitat International, 30(3), 482–499. https://doi.org/10.1016/j.habitatint.2004.12.004

Design for Manufacturing and Assembly (DfMA) - Prefabricated Prefinished Volumetric Construction Guidebook. (n.d.).

Design for Manufacturing and Assembly (DfMA) | Building and Construction Authority (BCA). (n.d.). Www1.Bca.gov.sg. https://www1.bca.gov.sg/buildsg/productivity/design-for-manufacturing-and-assembly-dfma

Hwang, B.-G., Shan, M., & Looi, K.-Y. (2018a). Key constraints and mitigation strategies for prefabricated prefinished volumetric construction. Journal of Cleaner Production, 183, 183–193. https://doi.org/10.1016/j.jclepro.2018.02.136

Hwang, B.-G., Shan, M., & Looi, K.-Y. (2018b). Knowledge-based decision support system for prefabricated prefinished volumetric construction. Automation in Construction, 94, 168–178. https://doi.org/10.1016/j.autcon.2018.06.016

Prefabricated Prefinished Volumetric Construction (PPVC) | Building and Construction Authority (BCA). (n.d.). Www1.Bca.gov.sg. https://www1.bca.gov.sg/buildsg/productivity/design-for-manufacturing-and-assembly-dfma/prefabricated-prefinished-volumetric-construction-ppvc

Thai, H.-T., Ngo, T., & Uy, B. (2020). A review on modular construction for high-rise buildings. Structures, 28, 1265–1290. https://doi.org/10.1016/j.istruc.2020.09.070