Rainwater harvesting intervention and its relationship with building codes is becoming a growing concern in modern construction. The aim of this paper is to present a road map for developing rainwater harvesting interventions, outlining the key steps required to achieve the desired outcomes. Qualitative methods were employed to assess the rainwater harvesting implementation. The findings show that the provisions for rainwater harvesting in the Malaysian Uniform Building By-Laws were inadequate to guide the local councils in building approval, inspection and enforcement. Another noteworthy finding is the lack of a specific intervention to ensure the success of rainwater harvesting law adherence, as well as the fact that the existing guidelines referred to were inadequate, indirect and irrelevant. In this paper, a simple direction for rainwater harvesting intervention is presented. This road map can be used to inform governments and researchers about the essential stages of intervention development in the interest of the by-laws adherence and the route to achieving Sustainable Development Goal 6: Clean Water and Sanitation. Implementing an effective intervention to improve government by-laws or building codes is essential for the successful management of water resources.