Oversizing urban areas in low-density regions

Since the 90s, the experience with the Municipal Master Plans, has been showing ambiguities in the enforcement of criteria regarding the delimitation of urban perimeters. This figure of spatial planning was expected to be an instrument for the consolidation of urban areas, ensuring their urban continuity. However, this goal was not always achieved. One of the problems is the oversizing of urban perimeters, having as a result the spread of new urban developments, the creation of urban voids or the underuse of facilities and infrastructures. In low-density regions, with a population loss, these problems are even more serious, given the weak demand of buildings and urbanizations. In this sense, this study is part of an on going research, and it will be focused on the study of oversizing urban perimeters in seven low-density regions in the Interior of Portugal. All of them having in common a land-use map coming from their Municipal Master Plans which are proposing the oversizing of urban perimeters compared to demographic or urban developing dynamics. The result of over nearly three decades of these spatial planning instruments are fragmented urban areas with low levels of urbanization and building execution. Even though they have all followed particular methodologies in order to identify the proper limits of urban perimeters, in all of them this process has occurred without the verification of the existing infrastructures. The conclusions have shown that in some cases the urban voids with no demand, correspond to 1/3 of the urban perimeters as a whole.