Integrated project delivery is advantageous in that it can reflect the constructor's expertise at the design phase. Furthermore, integrated project delivery allows project stockholders to promptly evaluate the financial performance of design decisions. However, there are many problems among existing quantity estimation processes, including human error, loss of information during data exchange and import-export, and time delays. These problems are major obstructions to the application of integrated project delivery. In particular, when it comes to rebar in structural works, errors generated during the drafting process of structural design information have a direct impact on estimation and construction. Such errors can be resolved by employing automatic quantity estimation software that uses the structural design information. In this regard, the present study proposes an automatic rebar estimation algorithm for use in integrated project delivery, the purpose of which is to further develop the software necessary for integrated project delivery. Continued development of additional algorithms for other types of resources as well as software capable of integrating these tools will lead to excellent decision-making support tools for project stockholders, including architectural designers.