evaluation of urban development. This allows evaluation of the usefulness and feasibility of the planning tools, strategic decisions, and financial sustainability of urban development. Urban sprawl must be minimized by regulation and alternatives, the physical plan must give priority to a concrete definition of the relationship between factors such as total surface area and zone density, maximum distances and general urban form, land use planning and means of transport. Compact forms are generally more sustainable and need to be encouraged by legal instruments. It is necessary, however, to respect certain proportionality between free (public or community) space and land reserved for construction. The dense urban model has a proportional limit between free space and the built environment. Plans fulfil the criteria for sustainability. They must foster integration between informal (family) and formal (business) economies, promote sustainable cycles of production and the recycling of waste, encourage the use of local, nonpolluting or recyclable materials and conserve natural resources (water and land). Recycling of land, unused areas, building materials should be a priority, as well as the use of degradable building materials. Local government should make sure that the plan is done according to basic principles for the planning of the system of open spaces, such as for example: the maintenance of natural elements and processes; the maintenance of the most singular physical characteristics, its elements and processes of perception, which gives identity to a specific landscape; the promotion of the integration among the elements and processes of urban occupation through open spaces, regardless their biophysical or visual attributes; the promotion of synergic urban design strategies between open and occupied spaces. Proximity is a governance principle that has a spatial dimension. On city and neighbourhood level, planning possibilities include:
Concentrating the working and living environment in walkable distance, maintaining or even improving the ecological quality. Production of consumption recycling services close to each other. Transport is the service in which intermediary cities have been innovative in the last decade: joining systems and fees, encouraging multi nodal systems, including cycling and walking facilities. To allow more urbanization along the existing public transport lines. Besides contributing to competitiveness, an investment in modern transport, attracting people to live in small centres that form a system and encouraging them to reduce the use of cars.