Summary- Reader Response Draft #3

The article “Design for Manufacturing and Assembly (DfMA” published by the Building Construction Authority (BCA) (n.d) describes Prefabricated Prefinished Volumetric Construction (PPVC) as a key component of DfMA technologies, DfMA plays a crucial role in Singapore’s Construction Industry Transformation Map (ITM), revolutionising the construction process by designing structures for manufacturing off-site in a controlled environment before final assembly on-site. PPVC, as explained on BCA website, involves constructing free standing 3-dimensional modules with internal finishes, fixtures and fittings in an off-site facility. This method reduces the manpower and time required for construction while ensuring safer, more conducive work sites with minimal impact on the surrounding environment. Off-site construction, as highlighted by Hwang et al. (2018a), has gained global recognition for its benefits and is extensively used in countries like Hong Kong (Chiang et al.,2006) and Spain (Pons & Wadel, 2011)

PPVC represents a game-changing approach that not only addresses conventional construction challenges but also emerges as a pivotal force in shaping the future of efficiency sustainability, and quality control.

Adopting PPVC offers a substantial boost in efficiency, as highlighted in BCA (2017) guidebook. The fabrication of PPVC can occur simultaneously in the factory while other on-site activities are ongoing, streamlining the construction process. By utilising PPVC, on-site activities can be greatly reduced. This method has the potential to enhance productivity by over 40% in terms of on-site manpower and more than 20% in time savings, depending on the project’s complexity. A case study by Nahmens and Ikuma (2012) examined the effect of lean construction on the economic aspect of PPVC, focusing on activities such as interior painting. The study analysed man-hours before and after implementing improvements like asquiring additional spraying equipment and standardising the process. The findings showed a reduction of approximately 31 man-hours per module and a 26.4% decrease in the total time required for interior painting. This reduction led to increase efficient in accordance with Singh et al, (2022). Unlike traditional construction methods, which are often carried out sequentially, PPVC allows for concurrent work, significantly reducing the construction schedule. Consequently, this acceleration in project implementation can lead to increased productivity.

 

PPVC also offers significant sustainability advantages compared to traditional on-site construction practices. According to Thai et al. (2020), the benefits include reduced environmental impacts. This method promotes material efficiency with on-site waste potentially reduced by up to 90%. In accordance with CyBe Constructions (n.d), PPVC contributes significantly to sustainable construction practices. Its modular construction concept facilitates the refurbishment and reuse of housing units further enhancing sustainability. Net-zero modules enabled by advanced technology and eco-friendly materials play a key role in this effort. PPVC method benefits from the controlled construction environment. By shifting more construction activities off-site, PPVC helps minimise environmental pollution by reducing dust and noise pollution. This approach minimises disamenities to surrounding neighbourhoods during construction. Additionally, prefabricating building modules results in cleaner worksites by reducing on-site construction waste, as highlighted by BCA (2017). In conclusion, PPVC presents significant sustainability benefits over traditional construction method. The reduction in environmental impacts, promotion of material efficiency, and facilitation of refurbishment and reuse highlight its contribution to sustainable practices. The use of advanced technology and controlled environments further enhance its environmental performance, making PPVC a promising approach for sustainable construction.

Lastly, PPVC enhances quality control through off-site fabrication in a controlled factory environment, resulting in higher-quality end product is delivered as highlighted by BCA (2017). Planning the sequence of work becomes more efficient with improved logistics coordination. PPVC is suitable for various multiroom accommodations including residences, institutions, hotels, hostels, nursing home and dormitories. Additionally, modules should be pre-assembled before inspection and finishing works such as checking the level and alignment, verticality, bulging, position of continuity, location of cast in items, twisting of modules, fire and corrosion protection, structural opening position and dimension and MEP (mechanical, electrical, plumbing) opening. According to Centre for Urban Sustainability, Nanyang Technological University. (n.d), there is a system which enhance PPVC quality. Stringent Quality Assessment (QA) and Quality Checks (QC) control is crucial involving China Construction (SP) Dev Co Pte Ltd (CCDC) Department’s Progress Quality Assessment System (PDAS). This system serves as the backbones of the audit check, ensuring that in-process and completed structural, architectural and mechanical & electrical (M&E) works meet the required quality standards based on BCA guidelines and tolerances. The majority of the final product is delivered from this controlled environment, ensuring increased reliability and superior finishing quality.

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

References

Building and Construction Authority. (n.d.). Design for Manufacturing and Assembly (DFMA). Retrieved from https://www1.bca.gov.sg/buildsg/productivity/design-for-manufacturing-and-assembly-dfma

Building and Construction Authority. (2017). Design for Manufacturing and Assembly (DFMA) - Prefabricated Prefinished Volumetric Construction. Retrieved from https://www1.bca.gov.sg/buildsg/productivity/design-for-manufacturing-and-assembly-dfma/prefabricated-prefinished-volumetric-construction-ppvc

Centre for Urban Sustainability, Nanyang Technological University. (n.d.). Introduction to PPVC (Prefabricated Prefinished Volumetric Construction). Retrieved from https://www.ntu.edu.sg/cus/research-focus/BIM/introduction-to-ppvc-(prefabricated-prefinished-volumetric-construction)

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

CyBe Construction. (n.d.). PPVC. Retrieved from https://cybe.eu/affordable-housing/ppvc/

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.2018.02.136Top of Form

Singh, A., Tiwari, S., & Dikshit, A. K. (2022). Critical review of lean construction research: A bibliometric analysis. Automation in Construction, 135, 103816. https://doi.org/10.1016/j.autcon.2022.103816

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