The Influence of Solutions Adopted at the Stage of Planning the Building Investment on the Accuracy of Cost Estimation

The accomplishment of building investments is a long-lasting process resulting in considerable financial outlays. Crucial decisions concerning construction solutions, technology of execution, organization of construction works are taken at the stage of planning and programming. At that time it is possible to predict the budget of an undertaking when it comes to preliminary cost estimation. However, taking accidentality, uncertainty of results, appearance of factors that were not planned earlier into account, it is important to know the total value of works. The solutions adopted at the stage of planning are reflected in costs in life cycle and determine the kind and range of possible risks. PERT approach used in the paper allows to present the costs of separate stages of the whole undertaking in ranges along with the probability of appearance.