The sustainable development and the urban form is a more pragmatic way of thinking. Achieving a sustainable shape for the city or the country will involve ensuring structures are capable, simple and flexible. The city must be able to support a cleaner environment. Seven design concepts are identified for the sustainable planning which is compactness, sustainable transport, density, use of mixed land, diversity, passive solar design and greening (Burnett, 2007). In addition to this are added the sustainable urban forms which are the neo traditional development, urban contention, the compact city and the eco-city (Jabareen, 2006).
The inflexible planning of cities has its roots in the 1950’s. It was at this period that post war development was at its heights. It impacted both the quality of development and also the physical planning. Most town planners worked with a utopian vision and forgot real life city planning (Taylor, 1998). This argument gives the assumption that all problems are of the past, however this assumption might not hold true for all countries. The rate of development of countries could and still does create various qualities of planning.
Hildebrand Frey is the protagonist of the theory of urban development and sustainable development. This theory is called the “urban cell theory” (UCT) (Frey, 1999). In this theory urban cells of the urban neighborhood are to be recalibrated so as to meet the design dimensions presented above. A biological connation is presented here. In biology a cell is alive when two or more cells near it are alive. Fewer cells near it would mean that the cell might get insulated and isolated and will die, on the other hand when it has more cells around it then it will die of overcrowding. The concept of the city could also be the same (Frey and Yaneske, 2007). It does have very strong interactions with the units around it, similar to the biological cell. A strong interaction which is complete with structural and functional integrity will make the cell more compact and functional. The compact and modular structure becomes more resilient (Frey and Yaneske, 2007).