Assessing sustainability practices across construction and post-construction phases in Nigeria’s AEC industry

Purpose This study evaluates the implementation of sustainability practices during and after the construction phases of building projects within Nigeria’s Architecture, Engineering, and Construction (AEC) sector. It aims to compare phase-based sustainability performance and identify implementation gaps that hinder lifecycle integration. Design/methodology/approach A structured cross-sectional survey was administered to 100 AEC professionals, including architects, engineers, builders, and sustainability consultants. Descriptive statistical analysis was conducted to assess twelve sustainability practices in both the construction and post-construction phases using mean scores and standard deviation measures. Findings Results indicate moderate to high implementation levels across both phases, with post-construction practices marginally outperforming construction-stage practices (construction: M = 3.68/5, 73.6%; post-construction: M = 3.72/5, 74.4%; both p < 0.001). Despite this progress, behavioural engagement, IoT-enabled monitoring, and structured sustainability reporting remain inconsistently implemented across both phases. Originality This study advances sustainability discourse in developing economies by providing a comparative, phase-based quantitative assessment of construction lifecycle practices, highlighting implementation disparities rarely examined within Nigeria’s AEC sector. Practical implications The findings underscore the need for institutional reforms, structured capacity building, smart technology integration, and post-occupancy performance monitoring systems to strengthen lifecycle-based sustainability implementation.