Abstract
In this study, as a cause of various problems in the Japanese construction industry, we focused on lot sizes of public works. The objectives of this study are to survey how the lot sizes of pulic works are determined, to examine how change of the lot sizes influences owners and contractors, and to make a proposal on desirable lot sizes of public works. As a first step to understanding influence of changing the lot sizes, we calculated how change of the lot sizes influence the indirect construction costs and the head office costs when the lot sizes of all public works are magnified. This calculation was done based on the cost estimation manual produced by the ministry of construction.
