Modelling building durations in Hong Kong

The duration of Australian construction has been modelled by a time-cost formula expressed in the form of T=KCB, where T is the actual construction time in working days, C is the final cost of contract in millions, K is a constant characteristic of building time performance, and B is a constant indicative of the sensitivity of time performance to cost level. This paper applies the relationship to building projects in Hong Kong using time and cost data from 110 projects. Regression analysis was used to compute the values of K and B and check how well the model actually fits, and the best predictor of average construction time of building projects in Hong Kong is found to be T=152C0.29. It is also found that the Hong Kong private sector takes a shorter time (120 days) to complete a hypothesized project with a contract sum of HK$1 million (at December 1994 price) than its government counterpart (166 days). The time-cost relationship serves as a convenient tool for both project managers and clients for predicting the actual optimum time required for delivery of a building project.