Understanding Apartment End-Use Water Consumption in Two Green Residential Multistory Buildings

The objective of this study was to gain a better understanding of the drivers of indoor water consumption in urban multistory residential buildings, to more accurately predict residential water demand, and to identify water saving opportunities. Water meters were installed at each end-use fixture in 15 apartments within two economically diverse green high-rise buildings. Infrared motion loggers recorded occupant presence. Interviews provided sociodemographic data and data about water consuming activities. The average apartment water consumption was 184L/[capita(cap)d] in Building #1 and 260L/(capd) in Building #2. A principal component analysis determined that tenant presence in kitchen, kitchen faucet water consumption, cooking frequency, bathroom faucet water consumption, bathtub water consumption, percentage of tenants going to work/school, percentage of children, and percentage of seniors were major contributors to the variability in total per capita water consumption. A water end-use model taking these drivers into account demonstrated that preferences in bathtub and shower consumption exceeded the effects of dish washing and toilet leaks. When considered in relation to overall water consumption in the city, the tenant per capita water consumption in both buildings was similar.