Performance Comparison of Design-Build Projects for Highways and Buildings

Design build (DB) is one of the most widely used alternative project delivery methods for constructing buildings and infrastructure projects in the U.S. According to a market intelligence study by RSMeans, 40% of nonresidential construction projects used the DB method in 2013. The use of DB in infrastructure and building projects has increased about twofold in the last decade. Various studies have compared project performance between DB projects and traditional design bid build (DBB) projects, and most showed that a cost as well as schedule advantage were the major benefits of DB compared to DBB. However, until now, no studies have been conducted to determine the differences in performance among DB projects or to compare cost growth with schedule growth in these projects. These were the focus of this study. Data from 26 highway and 31 building DB projects were collected, and the cost and schedule growth were compared to determine cost and time effectiveness. The results showed that there was no significant difference between the cost and schedule growth in highway and building projects. When schedule advantage was compared to cost advantage in these types of projects, it was found that owners were receiving significantly higher schedule advantage compared to cost advantage. This finding shows that DB delivery method should be used to save time rather than to save money.