Abstract The potential offered by non‐conventional water resources (rainwater) associated with high or low urban density in new housing in different rainfall zones (800–2300 mm) was studied. Ten cities in C olombia with over 250 000 inhabitants were used as a case study. The potential of substitution of tap water by rainwater according to population groups with different socioeconomic status was estimated. This study reveals the favourable conditions for rainwater harvesting in the C olombian context, and enables the linking of supply and demand issues related to local climatic and environmental sustainability in order to integrate the use of rainwater into urban housing projects. For the current consumption scenario (greater than 160 Lcd), rainwater becomes a potential replacement for mains water in urban areas with rainfall of above 1553 L/m 2 /year.