Exploring the feasibility of future housing development within existing cities: science-for-policy in the face of complexity and politicisation/

In cities around the world, housing demand is increasing rapidly. Since housing supply is inelastic, house prices are rising as well, which causes affordability problems. Although there is consensus about the need to raise production, there is debate about its location: within the existing city, on underused or derelict buildings and sites, or on greenfield land outside existing city boundaries? The question we address is how researchers on the science–policy interface can support these debates and facilitate evidence-based decision-making. We address two major problems while doing this: (1) the complexity of the object at hand, that is, of the development of urban systems and (2) the politicised nature of science-for-policy. The contribution of this paper is that it links complexity theory to the literature about science-for-policy, two usually unconnected literatures. An additional contribution is that it shows how the role of the scientist as ‘honest broker’, as developed by Roger Pielke, can be operationalised and applied to existing policy debates. We do that for the Dutch debate about housing development in existing urban areas.