The paper examines the possibilities of improving the accuracy of estimating the value of an investment and construction project based on various analysis and evaluation tools. Accurate estimates can be achieved using the Project Value Model at all stages of the project lifecycle. The stages of estimating the cost of an investment and construction project are considered, including costing, i.e. determining the costs of individual works depending on the calculation of the volume of work and pricing — determining the total cost of the project taking into account cost, profit and contingency provisions. The work carried out a comparative analysis of the methods of estimating the cost of the project: methods of high-level assessment, analog and method of parametric estimates, detailed assessment of the project costs, the use of which should be carried out iteratively. It is noted that risk management tools should be considered in combination with the project cost assessment due to the dependence of the goal in identifying and assessing risks with maximum performance and lowest cost. The article studied various approaches to assessment, in particular: estimating the cost of the project at the pre-investment stage in the form of a rough (approximate) value; estimate the project cost at the business planning stage as the estimated value of the cost justification Project Cost Estimation in the Process of Costing by Activity Type — Budget Cost Assessment Estimate the final planned project cost to be included in the project budget — accurately estimate the project cost. The article proposes the use of various tools and methods of risk analysis at the stages of the life cycle of an investment and construction project.