Potential impact of water-efficient plumbing fixtures on office water consumption

Estimations were made of potential water savings in offices through the use of water efficient plumbing fixtures required for new buildings by the 1989 amendment of the 1980 New York State Plumbing Law. Metered water consumption was divided into irrigation water for landscaped areas, cooling water, domestic water and that employed in restaurants and other non-office facilities. Water demand was estimated from assumptions about population density, building occupancy, the effect of the male-to-female ratio, consumption by toilets, urinals and washbasins, drinking water consumption, service use and building maintenance. Calculation for a typical office gave a value of 0.045 gpd per ft2, the same as that obtained by an independent method. Savings from the post-1992 regulations compared with pre-1980 and those arising from the 1980 law were then evaluated and were 69 and 44 per cent, respectively.