How can suburbs be built more densely? - International research project SUBDENSE starts

There is a shortage of housing in many cities. New construction and thus redensification on the outskirts of the city could provide a remedy. But the different logics of action of landowners and other actors often stand in the way. In the SUBDENSE project, an interdisciplinary team, including Mathias Jehling from the Leibniz Institute of Ecological Urban and Regional Development (IOER), is looking at this challenge of sustainable urban development. The project is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) and other international research agencies. 

The loosely built-up edges of large cities in Europe offer potential. Residential space could be created here, which is often hardly possible in the densely built-up inner cities. This would be crucial for climate protection and climate adaptation, because redensification in suburbs would avoid additional land consumption. Valuable soils, habitats for plants and animals, forest area and farmland would be preserved. Good arguments for building more densely in suburbs. But in reality, this plan often fails due to conflicts of interest and resistance on site. 

The international project SUBDENSE takes a look at this challenge of sustainable urban development. The project team is investigating how different strategies of land policy and the interests and actions of different local actors influence each other. On the plan to build more densely in the suburbs, political aspirations often collide with the interests, the "rationalities" of local actors. In the project, the researchers speak of "polyrationalities". This refers to the assumption that not all actors act according to the same logic, for example according to classical economic behavioural models. Accordingly, land policy must also position itself polyrationally in order to be able to react appropriately.

In the SUBDENSE project, the researchers look at these plural interests of the actors involved. Using six urban regions in Germany, Great Britain and France as examples, they first examine how different European suburbs have developed over the past ten years. They want to identify patterns and logics that underlie the use of space on the urban fringe. To do this, the project team combines geodata and spatial analysis with political science and social anthropological approaches of cultural theory and spatial planning. 

The researchers also want to look for positive examples in international comparison. In order to make the surveys tangible and comparable, the aim is to harmonise data and develop indicators for the different perspectives on the use of space. "In the end, the question is whether there are new models of spatial use that make it possible to densify urban space and create living space without compromising on the quality of living," explains Mathias Jehling from the IOER. "We are optimistic that we will find such examples in the case study regions." The data and results obtained from the project could eventually be incorporated into informal tools that support a new kind of planning for constructing on the urban fringe. 

The SUBDENSE project (Understanding polyrationalities of space, actors, and policies on suburban densification) is funded by the ORA7 collaboration of international research agencies. In addition to the Deutsche Forschungsgemeinschaft (DFG), these are the French Agence Nationale de la Recherche (ANR) and the British Economic and Social Research Council (ESRC). The funding volume is 1.2 million euros, of which the IOER will receive 320,000 euros from the DFG. 

The international project team is made up of researchers from four research institutions in Germany, France and the UK: Mathias Jehling from the IOER, Thomas Hartmann from the TU Dortmund, Sebastian Dembski from the University of Liverpool and Bénédicte Bucher from the Institut national de l'information géographique et forestière (IGN) in Paris.

Scientific contact at the IOER
Dr Mathias Jehling, e-mail:

The Leibniz Institute of Ecological Urban and Regional Development is jointly funded by the federal government and the federal states.

FS Sachsen

This measure is co-financed by tax funds on the basis of the budget approved by the Saxon State Parliament.