Causes and Effects of Building Collapse in Kano Metropolis: A Structural Engineering Perspective

Building collapse in urban Nigeria remains a persistent and deadly phenomenon, with the North West geopolitical zone recording several high-profile incidents in recent years. This study investigates the primary structural engineering causes of building collapse in Kano Metropolis, analysing fifteen documented collapse events between 2018 and 2023 using post-collapse investigation reports, photographic evidence, and structured interviews with engineers from the Kano State Urban Planning and Development Authority. The research framework draws on failure mode and effects analysis principles, categorising each collapse according to causal factors including design deficiency, material substandard quality, foundation failure, and illegal structural alterations. Findings indicate that the use of substandard cement and reinforcement bars, sourced from unverified local suppliers, was the leading contributory factor in nine of the fifteen cases. Foundation failures attributed to expansive soil conditions in the Fagge and Gwale local government areas were identified as a secondary cause, particularly in multi-storey residential conversions. The study further highlights the systemic challenge of unapproved building extensions that alter original load paths without engineering review. Regulatory enforcement is identified as critically insufficient, with building permit compliance estimated at below thirty percent. The study advocates for the establishment of a geotechnical hazard map for Kano Metropolis, compulsory structural peer review for buildings exceeding three storeys, and enhanced penalties for use of counterfeit building materials. Keywords: building collapse, Kano Metropolis, structural failure, foundation failure, substandard materials.