Urban fabric development: sustainable approaches

Urban fabric development and sustainability are two keywords circled in the research and academic literature. Here we are concerned mainly about professional practice. Urban fabric development and sustainability have three common pillars: Land use, urban densities, and transport system. Changing one of these pillars will have a concurrent influence on the other two pillars. In the following paragraphs, we will stand on the common criteria between these pillars when change applies to the urban fabric. Urban designers must achieve a good urban form at the same time they achieve sustainability. So what is a good urban form? And what is sustainability?

Researchers, practitioners, and academics have almost a consensus on the characters of a good urban form. These include discouraging zoning and achieving mix-use. Decentralization process should be slowed down. Extreme compact cities are not desirable. Decentralized towns around a city are preferable. Increase and promotion for inner green urban space. Public transport must be developed in all measures. People’s intensive activities must be drawn up around public transport nodes.

Sustainability is the efficient use of resources without damaging the balance of the ecosystem. Many countries in the world have developed their own green building and development systems. America and Europe have developed green systems for building and development (LEED, GREEN GLOBES, BREEAM, DNGB, GREEN STAR, MILJOBYGGNAD) you can check individually. Asian countries also developed their own systems (BEAM PLUS, CASBEE, BCA GREEN MARK SCHEME) take a look for further details. These systems core elements are to reduce utility consumption, reduce waste, using derelict land and developed land, decrease of environment damage by promoting clean energy and public transport, and achieving indoor and outdoor human use and well being.   

Urban fabric development common criteria

Professional practice & best practices pushed all urban fabric development towards achieving green building and development credits and rating system. We are going to go through land use effect on development. To develop land a planner or urban designer conducts various tests. These include land suitability analysis, carrying capacity analysis, committed land analysis, market forecast. Carrying capacity analysis is one of these major and important tests. From the planning point of view, carrying capacity can be defined as the ability of a natural or man-made system to absorb population growth, physical development, or intensity of use without significant degradation or breakdown ( Schneider, 1978).

Analyzing land use with these methods is very complex. For simplicity, to make land for residential use various factors must be considered suitable topography, near to water surfaces, near to recreation areas and parks, next to shopping areas, easy access and near work areas. Industrial land use should consider several factors available: raw material, transportation, market location, other industries location, utility supply, and regulatory laws. Land use for public building considers factors like avoiding locations increasing congestion, areas not disturbing business centers, and to be in transition areas between land uses. As we can see here that the common factor between these land uses for consideration is transport.

Researchers in transport planning link land use to employment. Land required for certain use is calculated as the number of acres needed for a particular industry, for example, is estimated by dividing the projected employment in that industry by an average number of employees per acre. Specifying land use leads to demand in travel. Defining land use leads to transportation implications. These are explored by simple trip generation, trip distribution, and modal split analysis (transport modeling). Opposite direction defining transportation alternatives are analyzed using simplified land developments modeling. An approach used in transport planning called “future urban spatial structure design approach” .   

Urban densities is another pillar urban designers consider in urban fabric development ( read here my paper review on high density development). Developed countries built various developments in suburban areas due to the demand for housing in quiet areas. These increases car ownership, increase in parking areas, heat island effect, pollution and gas emission, traffic congestion, inefficient land use, and decrease in public transport for low-density areas. Population growth and increase of employment opportunities in business centers caused population shift to city centers. To avoid car use, an approach was encouraged by sustainability organizations is to increase development densities. High-density development makes mass transit feasible, increase business power, and support energy system.  

Urban designers consider transport systems as a major component to design and plan in the urban fabric development. Developing transport systems requires good control on governance, finance, infrastructure, and neighborhoods. Public transport development reserves land for development, but increase land price within the accessed areas. Control on land that means ownership is a major factor in developing public transport. Building public transport nodes requires more than land ownership, but land uses that support the high cost of building them, which is high-density development. Here, high-density development is a critical factor in planning and designing transport systems and relevant transport nodes.

As we have discussed here that defining land use creates demand for travel. That means direct impact on developing transport system or constructing new transit system. Various models and calculations are run from two directions, land use and transport systems. If the new development or the existing urban fabric development requires transport system development, then two alternatives are introduced. If the area is developed towards low density, then mass transit will not be accomplished as it will not support the cost of implementing the development. Accordingly, car use and a new road network will be planned for construction.

So defining land use automatically requires change in transport system, adjusting transport system is determined by the urban density of the specified land use. Here we defined the concurrent influence of land use, urban densities, and transport system on the urban fabric development.