WHERE TO BUILD . Designing a GIS-based decision-support tool used to screen areas in the Netherlands for potential housing sites and determining their level of suitability based on stakeholder interests.

The Netherlands faces a critical shortage of affordable housing, which necessitates development
on new housing sites. However, certain challenges like limited space, lengthy building times,
and conflicting interests complicate the task of identifying suitable locations. This research
therefore addresses the central question of ‘where to build’, by development of a decision-support tool that can automate the screening process, and suitability analysis for new housing
sites. The study consists of a comprehensive literature review, identifying stakeholders,
associated with these processes. Their interests are identified and spatial characteristics that are
relevant for their interests are identified. By doing so, it becomes possible to come up with a
list of spatial criteria for development. The review also explores existing decision-support tools,
highlighting the effectiveness of Multi-Criteria Decision Analyses (MCDA) coupled with
Geographic Information Systems (GIS) in addressing spatial challenges. The research proposes
a schematic model for a universal GIS-based tool, consisting of three phases: setting up,
screening, and a suitability analysis. The model is implemented in QGIS, utilizing open-source
data from various plugins. A demonstration of the tool involves simulating five hypothetical
stakeholder scenarios, revealing distinct outputs based on different stakeholder weights. While
the model output appears valid and responsive to stakeholder inputs, the study acknowledges
the need for expert validation and suggests improvements, including case studies with real-life
stakeholders. Nevertheless, the research demonstrates the feasibility of developing a decision-support tool for housing site selection using open-source software.