IMPROVEMENT ON CONSTRUCTABILITY APPRAISAL SYSTEM (CAS)

Abstract

Buildability and constructability concepts have been introduced to the construction industry to effectively enhance building projects’ performance. The Building and Construction Authority (BCA) launched the revised “Code of Practice (CP) on Buildability” in April 2011. The revised code has two parts: Part 1: buildability (design stage) and Part 2: constructability (construction stage). However, Part 2: Constructability Appraisal System (CAS) is not comprehensive, and there is a room for improvement on Part 2: CAS.

The aims of this study are to: examine the strengths and limitations of BCA’s buildability and constructability assessment framework; find out the feasibility of proposed enhancements to BCA’s CAS framework; and design improvements to the BCA’s Part 2: CAS code.

After the questionnaire was developed, pilot studies using in-depth interviews were conducted to gain insights on issues related to the survey questionnaire. For the industry wide survey, data were collected via electronic mail from mainly contractors. 32 sets of completed questionnaires were received. Statistical tests were conducted. The overall results show that significant limitations exist in BCA’s CAS framework and a majority of the proposed enhancements are perceived by survey respondents as significantly necessary to improve BCA’s CAS.

This study contributes to knowledge by proposing an improved framework to BCA’s CAS. The improved framework can serve as a self checking tool for contractors, and an enforcement tool for BCA in improving constructability performance in Singapore’s construction industry. It is recommended that the BCA and construction firms adopt more comprehensive constructability framework design in this study to improve contractors’ constructability performance on construction sites.