The role of expert knowledge of the environment in decision-making about urban development has been intensively debated, largely in terms of a so-called ‘science-policy gap’. Most contributions to this debate have studied the use of knowledge in the decision-making process from the knowledge providers’ point of view. In this paper, we reverse the perspective and try to unearth how decision-makers use scientific knowledge in decision-making about an urban plan. We confronted municipal administrators, responsible for local urban development, with conceptions of the use of knowledge that were derived from the literature on this issue. From the reactions obtained, we conclude that, in the context of urban redevelopment, local administrators hardly perceive a barrier between themselves as decision-makers and experts – both environmental scientists and urban designers. They do, however, acknowledge that experts and decision-makers have distinct roles: unlike experts, local administrators have to balance all interests relevant to an urban plan. It is argued, therefore, that experts should engage in providing better decision frameworks rather than more or better knowledge.