Effect of Poor Project Planning on Construction Project Delays in Lagos State, South West Nigeria

Construction project delays represent one of the most persistent challenges in Nigeria's built environment sector, with significant cost and time overrun implications for public and private clients. This study examines the effect of poor project planning on construction project delays in Lagos State, South West Nigeria. A descriptive cross-sectional survey design will be employed, recruiting 200 construction professionals including project managers, site engineers, quantity surveyors, and contractors from ongoing building projects in Lagos Island, Lagos Mainland, and Lekki corridors. A structured questionnaire adapted from established delay factor indices will assess planning quality indicators and their contribution to project delays. Respondents will rate planning deficiencies across scope definition, scheduling, resource allocation, and risk identification. Descriptive statistics and multiple regression analysis will be used to identify which planning deficiencies most strongly predict delay occurrence. Existing literature from Nigerian construction projects consistently identifies inadequate planning as a leading cause of cost overruns and schedule slippage. This study adds contemporary Lagos-specific evidence to that body of knowledge and provides practical recommendations for construction firms and the Lagos State Ministry of Works. Findings are expected to support improved planning frameworks for urban infrastructure and residential projects across South West Nigeria. Keywords: project planning, construction delays, Lagos State, cost overrun, construction management