This thesis presents factors relevant to determining a design professional's liability for inaccurate cost estimates. A study of the literature related to different types of estimating methods was performed to determine what other authors have stated the accuracy to be for the respective type of estimate. Standard form contract documents of the American Institute of Architects and Engineers Joint Contract Document Committee were compared to determine the design professional's duties in meeting the requirements of the contract. Appellate court cases dealing with disputes involving inaccurate cost estimates were identified and evaluated to determine the key and consistent issues and rules applied by the courts. The cases are arranged by the primary interpretation rule which was instrumental in determining the outcome. The objective is to develop a flow diagram that owners and design professionals can use as an interpretive guide to assist them in understanding their requirements and liabilities for cost estimates. By formulating this basis of understanding of requirements, the parties will be able to practice claims prevention and avoid costly litigation.