Investigation of Project Delivery Performance Under Design-Build Contracts in the FCT

Design-build procurement is increasingly adopted for public infrastructure projects in Nigeria as a means of improving delivery speed and cost certainty relative to traditional sequential procurement. This study investigates project delivery performance under design-build contracts in the Federal Capital Territory, examining time, cost, and quality outcomes for projects completed between 2019 and 2024. A quantitative research design was employed, with 82 respondents comprising quantity surveyors, project managers, and Ministry of FCT officials. Project performance data from 28 design-build contracts were analysed using deviation analysis, descriptive statistics, and comparative analysis against benchmarks from traditionally procured projects. Findings show that design-build projects in the FCT demonstrate better time performance, completing on average 14% closer to planned duration than comparable traditionally procured projects. However, cost performance does not differ significantly, with design-build projects recording average cost deviations of 16.2% compared to 19.4% for traditional contracts. Quality outcomes are more variable in design-build arrangements due to reduced client control over specification details. Recommendations include the development of output-based specification standards for design-build FCT projects, enhanced post-award monitoring protocols, and mandatory quantity surveyor involvement in employer's requirements documentation. This study contributes to procurement selection literature for the FCT and North Central Nigeria. Keywords: design-build, project delivery, FCT, procurement performance, quantity surveying