Evaluation of Building Collapse Incidents in Lagos State: Causes and Contributing Factors (2015-2023)

Building collapse in Lagos State remains a recurring public safety crisis, with multiple incidents recorded annually causing fatalities and property losses. This study evaluates building collapse incidents in Lagos State from 2015 to 2023, identifying structural causes, contributing factors, and the distribution of incidents across building types and locations. Secondary data from the Lagos State Building Control Agency incident records, Lagos Emergency Management Agency reports, and newspaper archives were compiled and cross-referenced to produce a verified database of 68 documented building collapse incidents. Each incident was categorised by building type, age, number of floors, structural system, probable cause, and casualty data. The most probable cause was assessed using available investigation findings. Results indicate that residential buildings account for 82 percent of collapses. Substandard construction materials and inadequate structural design are cited as the primary cause in 47 percent of incidents. Illegal building modifications (additional floors without engineering assessment) account for 23 percent. Foundation failure in poorly prepared ground represents 18 percent of cases. Buildings between 5 and 20 years of age are most frequently involved. Professional supervision was absent in at least 74 percent of cases with available documentation. The study recommends a mandatory structural integrity certification programme for buildings above three storeys, strengthened enforcement of professional oversight requirements by the Council of Registered Builders of Nigeria.

Keywords: building collapse, structural failure, Lagos State, construction quality, building regulation