The course of major investment constructions does not resolve without complications. It often results in time and cost deviations. This is an especially delicate matter when it comes to public investments. This thesis describes the course of construction through public procurement. It starts with a general description of the facility and the objective of the investment, followed by an inventory of planned works on the basis of which the tender ocumentation is prepared. On the basis of the tenders, the contractor with the cheapest offer is selected, followed by the signing of the construction contract. After just a short time of executing construction works it is revealed that additional works will be required and that the construction time will be extended. The reasons for the agreement to the annex are described along the thesis. Finally, the comparisons of the engineering estimate, the contract value and the final value of the works are shown and described.