Sustainability begins with the recognition that we live on a planet with two opposing domains. We began in the first and now reside in the second. Linnaeus began to classify the Kingdoms of the Natural Domain around 1730, but overlooked The Built Domain and its four divisions: Shelter, Movement, Open Space and Life Support. It was a negligible factor during his time, but has grown into a competing artificial presence. This is a contest we cannot win in a universe that does not compromise with ignorance. It is why every acre of land is precious; why we must learn to live within limits; and why we must use each acre wisely as we attempt to shelter growing populations without consuming their source of life.
The consumption of land begins with the concept of property. I won’t even attempt to address this issue except to say that it has been the foundation of perpetual conflict, and that our current legal concepts will either appear anachronistic in time or become extinct. Adaptation is required and conscious adjustment is not inevitable, but I will leave its legal form for others to debate. My objective is to provide the tools needed to evaluate shelter options within sustainable limits defined by the science of others.
After Apollo 11, most will agree that the Earth is a finite resource protected by a thin film of atmosphere at risk; and that it exists within a universe defined as infinity. Therefore, the development capacity of land to provide shelter for growing populations becomes an issue of survival, since it is also a source of life that can be consumed. In other words, the built environment competes for land with the natural environment and survival hangs in the balance.
Land is used by four divisions within the built environment. The Shelter Division is served by the Movement, Open Space and Life Support Divisions. The relationship between building mass, pavement and open space within the buildable area of the Shelter Division is called intensity, which can be magnified by the surrounding intensity of its supporting divisions. Shelter intensity is expressed as the gross building area constructed per acre of buildable land available. Shelter capacity is found when gross building area is multiplied by the population anticipated per 1,000 square feet of building area forecast. The activities sheltered by building intensity combine to establish the social and economic characteristics of urban form.
Intensity options can be predicted with Development Capacity Evaluation software (DCE) based on the forecast model chosen and the values entered in its design specification template, and hundreds can be forecast in the time it takes to sketch one. The evaluation of these predictions can help us learn to use each acre wisely.
There has been no adequate definition of “over-development”, so the debate has wandered in a forest of detail and emotional confrontation that has only led to annexation, sprawl and blight. Debate has been limited by the language available, and DCE has been written to expand this vocabulary with accurate predictions of building capacity options. This may improve our ability to shelter growing populations within sustainable limits.
Intensity and context combine to create neighborhoods, districts, cities and regions. When the equations of intensity embedded in DCE software are linked to the mapping power of geographical information systems (GIS), the three-dimensional potential of urban form will emerge as options expressed in a visual and descriptive language. This can lead us toward life within limits that protect the health, safety and welfare of two worlds that now compete for survival.
Intensity options represent context choices. If we must learn to live within limits, then both intensity parameters and context design are critical to our health, safety and welfare. Within all divisions of the built environment, context is the form, function, appearance and arrangement of building mass, pavement and open space within the intensity parameters established. The most prominent parameters have been land use and transportation regulations, but our lack of ability to forecast intensity and correlate socio-economic benefit has produced a sprawling attempt to return to the farm.
Context is mute testimony to a great number of tactical design decisions made to achieve strategic leadership objectives. Strategy and tactics are lost without a goal, however. In this case, the goal is to create a Built Domain for mutual survival that does not threaten its source of life -- The Natural Domain. It is a worthy purpose for our continued presence if we can accept our stewardship responsibilities.
Author Note: Portions of this article were excerpted and edited from the second edition of my book, Land Development Calculations, and its attached forecasting software, Development Capacity Evaluation, v2.0 published by The McGraw-Hill Companies, 2010.