Cognitive Factors and Self-Reported Waste Minimisation Practices Among Construction Professionals

Abstract

Construction waste minimisation remains a persistent challenge in developing country contexts, where technical and regulatory deficiencies are often compounded by limited behavioural evidence on how professionals understand and respond to waste generation. This study examines the awareness, attitudes, perceptions, and self-reported waste minimisation practices of construction professionals in Lagos, Nigeria, to clarify how these cognitive factors relate to waste minimisation. Using a quantitative cross-sectional survey design, data were collected from 243 construction professionals through a structured questionnaire and analysed using exploratory factor analysis, such as the relative importance index, the Kruskal–Wallis H test, and Spearman’s rank correlation. The findings indicate a high level of awareness of waste reduction strategies, with organised waste sorting for material reuse ranked the highest (RII = 0.868). However, 54.3% of respondents still perceived waste as an inevitable by-product of construction projects, revealing an important cognitive–behavioural gap. Spearman’s rank correlation showed no statistically significant association between awareness and attitudes (r = 0.113, p = 0.079) and no significant association between awareness and perceptions (r = 0.049, p = 0.452). A statistically significant but weak positive association was found between attitudes and perceptions (r = 0.204, p ≤ 0.001), which is consistent with the Theory of Planned Behaviour (TPB) theoretical expectations but does not constitute a direct test of the full TPB model. The study contributes context-specific behavioural evidence showing that awareness alone may be insufficient to support waste minimisation unless accompanied by more favourable perceptions of feasibility and value. These findings have implications for behaviourally informed policy, professional training, and circular construction strategies in Nigeria and similar contexts.