A Review of RWHS Adoption in Non-Domestic Sectors

Rainwater harvesting systems (RWHS) are increasingly being adopted globally as part of green infrastructure to complement climate change adaptation and sustainable stormwater management. This study reviews the adoption of RWHS in non-domestic sectors, including commercial, industrial, and institutional settings, situating the topic within the broader challenges of water security in urban areas. This review aims to synthesise existing evidence on the key drivers, barriers, trends, and research gaps shaping RWHS adoption beyond the conventional domestic household scale. Following the PRISMA 2020 guidelines, peer-reviewed manuscripts published since 2000 were systematically identified and screened from the Scopus and Web of Science databases, focusing explicitly on adoption-related outcomes in non-domestic contexts. The findings indicate that RWHS adoption is primarily driven by anticipated water bill savings, sustainability, corporate environmental commitments, and stormwater management benefits, while major barriers include high initial capital costs, regulatory uncertainty, technical and maintenance complexity, and concerns regarding water quality and system reliability. This review also reveals sector-specific trends, such as the integration of RWHS with green building certification schemes and smart water technologies, and the prioritisation of process and utility water uses in non-domestic sectors. Overall, the findings indicate that non-domestic RWHS have substantial potential to contribute to sustainable stormwater management, but wider uptake depends on targeted policy support, economic incentives, clearer regulatory frameworks, and improved technical guidance, alongside further empirical research addressing the identified knowledge gaps.