The article explores how accurately estimating costs in the early stages of construction projects can be improved by considering and managing risks. By analyzing the relationship between design stage cost estimates and risk-contingency reserves, the researchers aim to enhance the reliability of budget planning for building projects. They reviewed existing literature to identify key factors affecting cost estimation accuracy and developed theoretical concepts to ensure cost certainty. The study emphasizes the importance of incorporating risk estimates in cost planning to achieve project objectives related to cost, time, and quality targets.