Another important design consideration at the Cityscape scale is the limit or “edge” of the built environment–beyond which the natural environment predominates. In our era, this is often not clearly defined. When cities start to spill over in a non-planned manner (sprawl) into rural areas or countryside, the utility and beauty of both are often compromised. A clear stopping point that defines the boundaries of urban built-up areas makes the adjacent open space more valuable, the urban space more efficient and both more aesthetically pleasing. The adjacent photo shows how the beautiful city of Cusco in Peru is sprawling, creating an indefinite “edge” to the place. As more and more buildings are located farther from the core area, roads and utilities become more expensive, the commute times longer, and the experience of living there less inviting. Certainly expansion of cities is necessary, but unplanned or unwise expansion has led to many functional and aesthetic problems. After density reaches a reasonable level, consideration should be given to establishing new centers responding to and respecting surrounding natural amenities. Geographical restraints like water bodies or steep surrounding mountains are often our planning allies, directing and limiting expansion and defining a reasonable edge to our developed areas. The city of Juneau in Alaska, the feature image on the previous page, is bounded by both water and mountains, making for a very clear limit of development, a very clear “edge”. Also, the peninsula city of San Francisco in California is the happy beneficiary of being surrounded by water on 3 sides which makes a beautiful and dramatic edge. But there have long been plans been plans to fill in large percentages of the San Francisco Bay, to allow easy adjacent expansion on flat land, to weaken or eliminate the natural “edge”. Clearly our awareness and respect for this design principle is necessary to prevent such disasters.
