Developing and implementing an empirical system for scoring buildability of designs in the Hong Kong construction industry

In view of the Construction Industry Review Committee's report which highlighted the unsatisfactory buildability situation in the Hong Kong construction industry, this study is aimed at improving buildability by providing a yardstick for measuring and appraising the buildability of different building designs. The research objectives are (i) to identify the most effective approaches for improving buildability; (ii) to formulate a scoring system to evaluate the buildability of different design components; (iii) to devise a Buildability Assessment Model (BAM) based on the scoring system for use in Hong Kong; (iv) to validate the BAM; and (v) to develop strategies for improving buildability using the BAM. Amongst alternative means as reported in the literature, the quantifying assessment of designs was found to be the most practical and successful approach in improving buildability. Upon evaluation of contemporary studies in quantifying design buildability, the Buildable Design Appraisal System (BDAS) in Singapore has been demonstrated as being suitable for adaptation in Hong Kong. The proposed Buildability Assessment Model (BAM) has been established through carrying out a series of structured interviews and questionnaire surveys. The BAM can be used to assess buildability of designs by focusing on 6 design components, namely: (i) Structural Systems; (ii) Slab Systems; (iii) Envelope Systems; (iv) Roof Systems; (v) Other Buildable Features (including Internal Wall Systems, Finishing Systems, Building Services Aspects and Building Features); and (vi) Site Specific Factors. For other design features which have not been covered by the BAM, an Open Score up to 10% maximum is given. Upon establishment of the BAM, the validation process has been undertaken and refinement made. The proposed BAM contributes to existing knowledge by providing a yardstick for buildability comparison amongst different designs, thereby serving as an incentive for buildability enhancement in Hong Kong. Eventually, recommendations have been made to enhance the implementation of the BAM such that in the long run, an increase in productivity and saving in manpower requirements on building sites can be achieved.