A scoping review of plastic waste bricks in residential construction: Opportunities and challenges in Africa

Plastic waste and housing shortages coexist across Africa, demanding sustainable construction innovations. This scoping review examines plastic waste bricks (PWBs) as an alternative to conventional masonry units. Using the framework proposed by Arksey & O'Malley and adapted by Levac et al. (2010), we conducted searches across five databases: Scopus, Web of Science, Google Scholar, ScienceDirect, and AJOL. We found 18 articles published between 2016 and 2025 that met the inclusion criteria. The findings revealed compressive strengths ranging from 12 to 25 MPa, potential construction cost savings of approximately 30%, and significant environmental benefits, including reduced CO₂ emissions. To assess the quality of the included articles, we used the CASP checklist and the Cochrane risk of bias tool. The majority of the studies reported experimental trials; however, only a small proportion assessed potential impacts on policy or socio-economic feasibility. We recommend multidisciplinary pilot projects and standardised LCA protocols to bridge lab-scale promise and scalable, inclusive urban development in Africa.