Modeling water use for sustainable urban design

Achieving sustainability on an urban scale is an overwhelming problem. We can address this by dividing the problem into manageable proportions. Environmental impacts of urban design fall into measurable categories, for example, air quality, biodiversity, solid wastes, water and wastewater, hazardous materials, and impacts of nonrenewable energy use. Such measures are incorporated into building rating systems as a way of codifying sustainability. In this chapter, to illustrate such codification, we examine water use as well as generated wastewater according to the requirements of a specific sustainable building rating system. Conventional calculations are coupled with building information modeling to illustrate the overall effects of parametrically selecting fixtures, systems and materials to control the use of potable water. We further demonstrate how this approach of combining parametric building information modeling with measures of their environmental impacts can be employed on an urban scale, thereby, guiding the design of sustainable urban spaces.