Comparing time and cost performance of DBB and DB public construction projects in Kuwait

Kuwait is an enormous construction site as many vital public projects are under construction or in preparatory stages to achieve the vision of a New Kuwait by 2035. However, the new Public Tenders Law No. 49 of 2016 authorized the sole operation of the Design-Bid-Build (DBB) method as the delivery system method, preventing the employment of Design-Build (DB). Hence, this research undertook a comparative analysis of cost and time performance of DBB and DB public construction projects in Kuwait for the first time, marking the originality of this study. Moreover, 160 projects were collected from four government entities. Then, the total collected projects were categorized based on contract types and project sizes depending on contract cost. This research has recognized that DB has superior performance compared to DBB regarding cost growth for all collected projects, both contract types, projects of less than 300,000 KD, and projects between 300,000 and 12 million KD. No statistically significant differences between DBB and DB projects regarding schedule growth were found for all collected projects, both contract types and project sizes. Furthermore, the findings indicated that the DBB projects’ construction intensity was faster than that of DB projects with a value between 300,00 KD and 12 million KD. For projects that had a value of more than 12 million KD, the DB projects’ construction intensity was faster than that of DBB projects. Hence, it is concluded that the issue is not with the DB delivery systems themselves, but rather with the deployment of these systems.