Modelling the Relationship Between Project Governance Structures and Cost Performance in Public Building Projects in Nigeria

Project governance encompasses the systems of accountability, decision-making authority, and oversight that shape how construction projects are managed and controlled. This study models the relationship between project governance structures and cost performance outcomes in Nigerian public building projects, drawing on data from 22 ministries and agencies in the FCT, Lagos, and Kano. A quantitative dominant mixed-method design was used, with 198 respondents including ministry officials, quantity surveyors, contractors, and auditors completing structured instruments. Governance variables including board oversight frequency, financial approval authority levels, audit committee engagement, and quantity surveyor appointment were operationalised and regressed against cost deviation indices. Path analysis revealed that quantity surveyor appointment, financial approval clarity, and external audit engagement are the strongest governance predictors of cost performance, explaining 58% of variance in cost deviation outcomes. Weak governance structures are found to amplify the effect of exogenous risks such as inflation and contractor default on final project costs. The study also finds that arm's length governance models, where project management is contracted to independent firms, demonstrate better cost outcomes than internally managed government projects. Recommendations draw on governance reform theory and are directed at institutional design in Nigeria's public construction sector. This study makes an original theoretical contribution by applying governance theory to construction cost management in a developing country context. Keywords: project governance, cost performance, public buildings, Nigeria, structural modelling