Introduction in the subject
Cities within Europe are developing unsustainable urban structures. This is mirrored in the fact that land consumption continuous to be on the rise throughout Europe. Land consumption can be related to various factors: the economics of globalization, preference for single house living, land price dynamics, increased mobility, existing national and local policies, among other factors. In the longer term, expansive development will weaken our ability to deal with the pressing trends expected in the future: climate change, demographic change, peak soil, peak oil, rising costs of infrastructure, to name a few. Land consumption also endangers the nutrition source of mankind.
For this background the circular flow land use management concept represents an integrative policy and governance approach. Its starting point is a changed philosophy with regard to land utilization. This modified land use philosophy can be expressed with the slogan “avoid – recycle – compensate” (Federal Office for Building and Regional Planning (BBR) 2006). More specifically, these points can be expressed by the actions of:
- Avoid – The conversion of now un-built open space or agricultural land into new developments is to be avoided.
- Recycle – Areas with uses that were once active and now exhibit no viable use should be recycled by either introducing new uses or through renaturation.
- Compensate – Compensation should be required when construction must take place on previously unbuilt land. This can be in the form of renaturation projects or through de-sealing measures in built areas, where soil sealing is no longer necessary.
Source: Federal Office for Building and regional Planning (BBR) (Ed.) (2006): Perspektive Flächenkreislaufwirtschaft special publications series for the ExWoSt research field Fläche im Kreis, Vol. 1. “Theoretische Grundlagen und Planspielkonzeption“, revised by Thomas Preuß et al. (German Institute of Urban Affairs et al.) and Fabian Dosch et al. (BBR), Bonn.
Thus, similar to the recycling-based principles which have become commonplace in recent years in areas such as waste and water management, circular flow land use management should become an established policy for sustainable land utilization. Soil has to be recognised as a scarce resource like some metals etc. Therefore material cycles serve as a model for circular land use management: the constructed city is understood as a system with a structural makeup which is subject to various usage phases and where, in certain instances, entire districts and industrial areas are dismantled and made suitable for subsequent use. During this entire process, the total area of land used should remain the same. Structures no longer fit for reuse are demolished or renaturalised. Measures for development of the existing built-up areas are suggested for all regions – regardless if they are growing, stable or shrinking. The idea of a “circular flow” of use thus seizes upon the notion of a use cycle in the allocation of building land, development, use, abandonment and reuse.