Modeling construction time in Spanish building projects

The literature states that project duration is affected by various scope factors. Using 168 building projects carried out in Spain, this paper uses the multiple regression analysis to develop a forecast model that allows estimating project duration of new builds. The proposed model uses project type, gross floor area (GFA), the cost/GFA relationship and number of floors as predictor variables. The research identified the logarithmic form of construction speed as the most appropriate response variable. GFA has greater influence than cost on project duration but both factors are necessary to achieve a forecast model with the highest accuracy. We developed an analysis to verify the stability of forecasted values and showed how a model with high values of fit and accuracy may display an anomalous behavior in the forecasted values. The sensitivity of the proposed forecast model was also analyzed versus the variability of construction costs.

The study presented in this paper was mainly funded by a research grant awarded by the Office of the Vice President for Research, Development and Innovation of the University of Alicante (resolution 22 December 2011). It has also been partially funded by the Spanish Government through the project TEXTMESS 2.0 (TIN2009-13391-C04) and by the Valencian Government through the project PROMETEO (PROMETEO/2009/199).