Prefabricated Prefinished Volumetric Construction (PPVC) 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.
Why use PPVC
- Improved Productivity– PPVC can improve productivity by up to 40% in terms of manpower and time savings, depending on the complexity of the projects.
- Better Construction Environment– As the bulk of the installation activities and manpower are moved off-site, it minimises dust and noise pollution and improves site safety.
- Improved Quality Control– Off-site fabrication in a controlled factory environment can produce higher quality end products.
What to consider when using PPVC
- Early contractor involvement– Developers/project managers should obtain inputs from the PPVC supplier or manufacturer as well as the Main Contractor at the design stage. This helps in developing effective technical solutions for the project. For example, the choice of material will dictate the size and number of modules in the design as weight is a major consideration for the hoisting of the modules.
- Site/project management – The condition of the roads surrounding the project must be able to accommodate the weight and size of the PPVC module delivery. Access to and within the site must be able to accommodate loaded trailers. It may not be practical to store many large PPVC modules on-site, and a Just in Time (JIT) installation would prevent unnecessary double handling. The crane deployed on-site must be able to handle the weight of the PPVC modules and its location should be properly planned so that it can reach all blocks for the installation of modules.
- Maintenance, replacement and renovation– It is good practice for developers/builders to provide a homeowner user manual of the PPVC upon completion of the project. For any renovation works, it is recommended for homeowners to engage a renovation contractor, who would use the appropriate tools and follow the instructions provided in the homeowner user manual.
Compliance to regulation
- Requirements by respective agencies– The design, construction and installation of the proposed PPVC system for building construction shall comply with the requirements by the respective agencies such as BCA, Land Transport Authority (LTA), Ministry of Manpower (MOM), National Environment Agency (NEA), PUB, The National Water Agency, Singapore Civil Defence Force (SCDF), Urban Redevelopment Authority (URA), Housing and Development Board (HDB) and JTC Corporation.
- PPVC Acceptance Framework– To ensure that the different PPVC systems being used are reliable and durable, BCA has set up a PPVC Acceptance Framework consisting of building regulatory agencies as well as industry experts to evaluate the design and materials used. PPVC suppliers and manufacturers who intend to supply their PPVC systems to be used at the mandated development sites should apply for acceptance.
- Sites with PPVC requirement–The use of PPVC is required for selected residential non-landed Government Land Sale (GLS) sites from 1 November 2014 onwards. Details of these sites and the mandatory PPVC requirements may be found in the Building Control (Buildability and Productivity) Regulations and in the Code of Practice on Buildability 2017. More information is also available in the circular issued on 30 November 2015.
Current trends and outlook of PPVC
- Growing demand for consultants and builders– With the growing number of projects using PPVC, there is a stronger demand for consultants and builders who are familiar with PPVC technology.
- Cost premium– Currently, the cost premium of concrete PPVC against conventional reinforced concrete construction is estimated to be less than 8%. With the increasing number of suppliers and lead demand, the cost premium is expected to reduce further. This reduced premium can be further offset by the other benefits of PPVC including earlier delivery, reduced transportation trips and a safer workplace.
Figure 1: PPVC module installation