Enhancements to the buildability framework

By BCA

With the target rollout of the enhanced Buildability Framework in the fourth quarter of 2020, Singapore’s building designers can look forward to more opportunities to creatively develop solutions that meet buildability requirements.

The framework focuses on getting companies to integrate Design for Manufacturing and Assembly (DfMA) technologies in their projects. DfMA is one of the key pillars in the Building and Construction Authority’s (BCA) vision to transform the industry, shifting its reliance on site workers to the use of prefabricated building components in projects.

Indeed, DfMA will soon become the default way of building as it helps companies build better quality projects in a shorter time, while improving site safety.

What is the Buildability Framework?

The buildability legislation was implemented in 2001 under the Building Control Act. The framework is a performance appraisal system that covers a wide range of building designs, systems and technologies for structural, architectural and mechanical, electrical and plumbing (MEP) works that focus on improving productivity, reducing site labour and raising the quality of completed projects.

Key changes in 2019

In December 2019, BCA unveiled initiatives to enhance the framework to drive greater adoption of DfMA technologies in construction projects.

1.Projects with GFA less than 5,000m2are exempted from the Buildability Framework

BCA recognises that smaller projects have more limited scope for prefabrication as we raise buildability standards. Therefore, the focus has shifted to larger projects for DfMA adoption as they are expected to deliver significant impact on productivity as a whole.

2.Large non-landed residential projects (GFA of at least 25,000m2)must meet a higher minimum Buildable Design Score (B-score)

To encourage designers to integrate DfMA technologies into their projects. BCA has raised the minimum B-score from 88 to 92, for projects submitted to the Urban Redevelopment Authority (URA) for Planning Permission on or after 15 December 2019.

3. In lieu of meeting a higher B-score, non-landed residential projects with GFA of at least 25,000m2can instead improve productivity by adopting suitable DfMA designs and technologies

This means that designers can choose from three solutions BCA deems acceptable, or fourthly, come up with a proposal (open option) that can achieve at least 20% improvement in productivity from 2010 level.

The three acceptable solutions are:

a. Adopting Prefabricated and Prefinished Volumetric Construction (PPVC)

b. High usage of prefabricated components in structural and architectural systems, and

c. High usage of prefabricated components in structural, architectural and MEP systems (at different level from b)

For details on the three solutions, read the 2019 circular on amendments to buildability and productivity regulations [PDF, 610 KB].

Building supply and capabilities for DfMA

As the supply of labour becomes tight, construction companies in Singapore are warming up to the use of DfMA. The adoption rate stood at 31% in 2019, compared with 22% a year earlier, according to a news report citing Minister of State for National Development and Manpower Zaqy Mohamad in Parliament on 4 March 2020.

Mr Zaqy added that the industry is “on track” to meet DfMA adoption of 40% in 2020.

Since 2010, Singapore’s construction industry has achieved a cumulative site productivity improvement of about 15%. This is expected to rise to 20% by the end of 2020, with the completion of more DfMA projects.

To date, more than 80 architectural, civil and structural and mechanical and electrical engineering consultancy firms, as well as about 60 builders combined have embraced various DfMA technologies in some 140 projects. The result? Completing higher quality projects in a more sustainable manner.

As demand for DfMA rises, the number of PPVC and Prefabricated Bathroom Units (PBU) systems has steadily increased in recent years, with 43 PPVC and 41 PBU systems as at April 2020.

Next steps

BCA will further enhance the framework in 2020 by making DfMA integral in all three components of building works: structural, architectural, and MEP works. This will encourage designers to choose from a wide range of DfMA technologies and apply them in their projects to raise productivity and quality.

Besides large non-landed residential projects, BCA will also introduce outcome-based solutions for other large buildings, including commercial and institutional, in the new framework.

BCA piloted the new framework in December 2019 and has been working with industry to gather feedback on the proposed enhancements ahead of its rollout later this year.