The most popular definition of sustainability can be traced to a 1987 UN conference. It defined sustainable developments as those that "meet present needs without compromising the ability of future generations to meet their needs"(WECD, 1987). Robert Gillman, editor of the In Context magazine, extends this goal oriented definition by stating "sustainability refers to a very old and simple concept (The Golden Rule)…do onto future generations as you would have them do onto you."
Sustainability embodies "stewardship" and "design with nature," well established goals of the design professions and "carrying capacity," a highly developed modeling technique used by scientists and planners.
These well-established definitions set an ideal premise, but do not clarify specific human and environmental parameters for modeling and measuring sustainable developments. The following definitions are more specific:
· "Sustainable means using methods, systems and materials that won’t deplete resources or harm natural cycles" (Rosenbaum, 1993).
· Sustainability "identifies a concept and attitude in development that looks at a site’s natural land, water, and energy resources as integral aspects of the development" (Vieira,1993)
· "Sustainability integrates natural systems with human patterns and celebrates continuity, uniqueness and placemaking" (Early, 1993)
In review of the plurality of these definitions, the site or the environmental context is an important variable to most working definitions of sustainability. This emphasis is expressed in the following composite definition:
Sustainable developments are those which fulfill present and future needs (WECD, 1987) while [only] using and not harming renewable resources and unique human-environmental systems of a site: [air], water, land, energy, and human ecology and/or those of other [off-site] sustainable systems (Rosenbaum 1993 and Vieria 1993).
These fundamental human-environmental exchanges of the community’s "site" were found very useful in developing critical "input – output" modeling techniques or indicators which directs the community’s regenerative process. This selected network of a community’s human and environmental interrelationships were measured and placed in balance by the selected set of integrated design and planning strategies.