The evolution of the use of prefabrication techniques in Hong Kong construction industry

The construction industry in Hong Kong heavily relies on conventional cast in-situ construction involving extensive use of timber formworks and wet trades. In 2001, the Construction Industry Review Committee report described the construction activities in Hong Kong as ‘labour intensive, dangerous and polluting’. Globally, however, the recent trend is prefabrication, which is being increasingly used in the building industry, alleviating some of the environmental burdens associated with conventional construction. Very few studies have assessed the sustainable construction aspects of prefabrication in dense urban environments in terms of economic, environmental and social benefits and limitations of using prefabrication. Prefabricated building components have been adopted in Hong Kong for over two decades for high-rise buildings from the public sector. There is a need to study the use of prefabrication in high-rise buildings, especially for projects in the private sector given the global trend towards sustainable construction. This research project aims to investigate the evolution and application of precast construction in high-rise buildings and assess the sustainable construction aspects of prefabrication in dense high-rise urban environments like Hong Kong. In this research, five major ways of collecting and analysing data are pursued, using a combination of quantitative and qualitative methodologies: questionnaire surveys, compilation of a database, detailed case studies of recently completed buildings in Hong Kong, face-to-face interviews, and site observations. The study reveals that a wider application of prefabrication in buildings in Hong Kong could significantly contribute to economical, environmental and social benefits, especially in dense urban environments. In the detailed case studies, on an average, a reduction of 65% of construction waste, 16% of labour requirement on-site and 15% of construction time is noted when adopting prefabrication techniques. The findings also reveal that prefabrication combined with modular design and standard precast elements saves time and construction/design costs, as the prefabricated building system is not reinvented for each project. The study suggests that a critical agenda should include the development of serious aspiration towards a more environmentally responsible and sustainable building industry (e.g.closed-loop material principles) to achieve a healthy built environment and efficient use of resources.