The article presents an office building life-cycle estimating possibility with the use of multiple-criteria evaluation and simulations modeling techniques. The first part describes the life cycle of an office building with a focus on the places where it is necessary to make strategic decisions. These decisions are most often associated with (the incurring of) high financial costs. It is, therefore, necessary to choose a tool supporting the decision-making process. Presents for evaluation several criteria were developed, a number of which concern office buildings. It should be remembered that the multiple-criteria assessment means not only the criteria but also weights which are assigned to them. The article discusses different ways of assigning weights to criteria, e.g. the Simos method. The use of several different methods of multiple-criteria evaluation was suggested, for example the method of weighted sum, the ideal point method and the entropy method. The analysis was based on simulation models. The full cost model was built in MS Excel. For modeling the Crystal Ball software was used. The software applied allowed not only to determine confidence in the selected scenarios, but also to point to the criterion or factor which has the greatest impact on the final result. Such information can be obtained through the use of sensitivity analysis.