ENHANCED BUILDABILITY FRAMEWORK: NEW CONSTRUCTABILITY SCORE AND ITS IMPACT ON SINGAPORE'S CONSTRUCTION PRODUCTIVITY

Abstract

Construction productivity is affected by several factors, with buildability being one of the most important. It has been the focus in the construction industry for more than 10 years now. While the Government realizes the need to cut down the industry’s reliance on foreign workers, it also recognizes that builders should pick up more advanced construction mechanization to aid their work process at site. Through the Enhanced Buildability Framework: Tightened BDScore and New CScore, the government seeks to achieve higher productivity improvement in the construction industry.

An examination of existing literature revealed the influence of buildability and constructability factors on productivity in the construction culture of Singapore. It also looks into the Enhanced Buildability Framework, particularly its effect on construction productivity improvement.

While the Buildable Design Appraisal System (BDAS) focuses on the usage of buildable designs during the upstream design process, the downstream construction methods and technologies should not be neglected. The introduction of Constructability Appraisal System (CAS) becomes necessary to tackle productivity improvements. Designers’ attention to buildable designs has to complement builders’ adoption of labour-efficient innovative methods, systems and processes in order to bring about greater ease in construction. Benefits include the reduction of manpower on site, which in turn leads to higher site productivity.

Since constructability is still a strongly debated subject, the objective of this research is to investigate its relevancy and importance to site productivity. The ultimate aim is to prove that the integration of BDAS and CAS can further enhance Singapore’s construction productivity. In view of this, their interrelationship was explored. The research will also quantify and qualify the effects and relative influence of the following buildability and constructability factors on its productivity respectively: (1) Labour- Efficient Building Design (BDAS) – (a) Buildable Design Features; (b) Labour-Saving Design; (c) Simple & Modularised Design, and (2) Construction Systems & Processes (CAS) – (a) Labour-Efficient Construction Methods; (b) Good Site Practices; (c) Good Industry Practices.

To achieve this objective, a sufficient amount of data was collected, via survey questionnaire and interviews with the authority and building professionals, and analysed using one-sample t-test to see the significance of the results. Pearson’s bivariate correlation analysis has also been adopted to verify their correlation and significance with one another. Through these methods, the effects and relative influence of buildabilty and constructability factors examined are determined. The findings show both significant and insignificant effects of BDAS and CAS, depending on the respective factors, towards the Enhanced Buildability Framework in bringing higher productivity improvement. These findings could provide designers and builders with feedback on how well their design and construction methods/technologies fit in with buildability and constructability concepts, and the consequences of their decisions on site productivity. Subsequently, the depicted patterns of results may provide guidance to construction-related personnel for effective planning and labours utilization.