A Study on the Characteristics of "Early Contractor Involvement Method" in Public Project in Japan

In recent years, Owner, Architects, and Contractor are increasingly collaborating with each other from pre construction phase in construction projects, which is called Early Contractor Involvement (ECI). In Japan, the ECI method has been introduced in several public building projects since 2015. The purpose of this study is mainly to clarify the characteristics of the ECI method in Japan and to compare the contract clauses of the ECI method in the UK and the USA. The results of the survey are as follows. (1) the ECI method was supposed to make it possible to achieve appropriate quality, cost, and construction period by reflecting Contractor's technology and know-how in the design documents and specifications. (2) According to the database, there were 27 cases of the ECI method in Japan from 2015 to 2021, of which 13 cases for which bidding information could be obtained had a variety of technical proposals, mainly VE proposals, depending on the project characteristics. (3), Japan's ECI method has very much in common with SBC + PCSA in the UK. On the other hand, ECI Method in Japan differs from in the UK in that Owner, Architect, and Contractor enter into a partnership agreement, which is similar to ConsensusDocs CD541 in the USA. (4) The ECI method in Japan has the following problems: Owner depends on Contractor for cost control, the division of roles among project members is complicated, and more work from Owner than the DBB method are required.