Studies on Household Water Consumption and Water-Saving Solutions for Four Cities in the Red River Delta (Hanoi, Hai Phong, Hai Duong and Nam Dinh)

Abstract

Apart from energy efficiency, water saving has become a key standard for green buildings worldwide and will soon be a compulsory requirement for sustainable housing design in Vietnam, especially when the demand for clean water tends to rise whereas water supply under the impact of on-going climate change may be insufficient. In this context, household water consumption in cities, particularly in major cities, should be analysed to find out common issues and to highlight different points as well among several housing patterns and groups of users. In total, 198 households from four cities in the Red River Delta of North Vietnam (Hanoi, Hai Phong, Hai Duong and Nam Dinh) were surveyed in 2018. Before taking into account the potential of using grey water after treatment, rainwater—because of its abundance, simple technique, low-cost appliances and high applicability—should be collected and used in place of tap water for certain purposes. Two villas and four row-houses in Hanoi have been selected for further investigations. In each case study, it is possible to calculate the level of water saving based on some input data and its significant contribution to a more sustainable city in Vietnam can be demonstrated.