Purpose: The purpose of this study is to provide an effective construction project cost estimation tool for preparing a business plan of healthcare facilities which can be practically used for development projects. Methods: In order to provide a tool for calculating construction project costs, this study analyzed the Building and Related Laws, the Building Technology Promotion Laws, the Ministry of Land, Infrastructure and Transport notifications and directives, the Ministry of Trade, Industry and Energy notifications, the detailed guidelines of the Ministry of Strategy and Finance, the Building Service Industry Promotion Acts, various certification standards, actual project budget calculation cases, etc. with advices from related experts. Results: 1) Construction cost is classified into construction costs, architectural design costs, supervision costs, incidental costs, and each sub-element. In particular, since there are many incidental cost items, essential items to be reviewed during planning are derived and costs are calculated according to appropriate consideration criteria. 2) Criteria for Payment calculation mainly applies the construction cost rate method or the actual cost fixed amount method in consideration of the characteristics and scope of work. Implications: There are many calculation factors that need to be applied to the construction project cost. Therefore, it is necessary to organize the calculation process more clearly.