Construction time information system for the building industry

The paper describes a computerized construction time information system for time planning of buildings at early stages of design. A sample of 29 commercial, privately funded buildings was used to develop the proposed model. A procedure for extending the model to other project categories is shown. Multiple linear regression analysis of sample data shows that the durations of activity groups: substructure,superstructure, cladding, finishes, services and their sequential start – start lag times can be predicted from 12 variables: grossjloor area, area of groundpoor, approximate excavated volume, building height,number of storeys, end use, cladding type, presence of atrium, building location, intensity of services and site accessibility. An experiment involving nine planners and three office projects showed that the time predictions of the model fall within the distribution of planners' estimates and are tatistically indistinguishable from them. Therefore, the model can produce reliable estimates of construction times.