The current Dutch housing domain is characterised by injustices on multiple scales, such as a shortage of housing, disparities in well-being across regions, and unaffordable housing. This situation can partially be attributed to spatial planning practices focused on promoting growth-oriented economic thinking. These contemporary planning practices can be argued to be socially and spatially selective and to have a short time horizon. While some injustices remain unresolved, others are exacerbated by contemporary planning practices. The aim of this research has been to develop a justice framework which helps spatial planners address, instead of perpetuate injustices. This is approached through the question: To what extent can a framework based on justice values help spatial planners design for justice in the housing domain in Dutch regions?

This has led to the development of a justice framework constructed from three core justice values: Sufficiency, Limitation and Opportunity. These are made more concrete to the housing domain through two applied values each: (I) Availability and (II) Acceptability for the quantitative and qualitative aspects of Sufficiency; (III) Sustainability and (IV) Moderation dealing with intergenerational justice and intragenerational justice for Limitation; and (V) Influence and (VI) Diversity related to opportunities to assert influence on the living environment and to choose a living environment. These applied values are further specified using housing dimensions and strategy directions in two consecutive rings.

The first advantage for spatial planners is that the justice framework summarises and combines several abstract justice theories into digestible values relevant to the Dutch context. To test and demonstrate the justice framework it has been applied to the case study area of the Regio Stedendriehoek, which enabled answering the research question. First the justice framework helps to structure regional spatial analysis and policy analysis on a wide range of justice values, which can bring to light different types of injustices. Second, based on the analyses, clusters can be made of areas with similar problems regarding the applied values, which helps determine which type of strategies require priority in different areas. Then, based on these priorities, strategies can be developed using the outer ring of the justice framework. The justice framework helps to structure strategy development per applied value, but the justice framework can also be used as a tool to assess whether strategies can contribute to solving injustices for different applied values. In this way fruitful strategies can be prioritised and interventions that cause conflicts between different justice values can be avoided or mitigated.

Different government bodies, from the European Union down to the Port of Rotterdam Authority have implemented the policy goal to become circular by 2050 to minimize demand and dependence on finite resources. However, a circular economy - an economic model in which materials circulate in closed loops and waste is viewed as a resource - is vastly different from the current linear system of extraction, consumption and waste. The plastics industry that is currently present in the port of Rotterdam is one such industry where large amounts of raw material is being used and large amounts of waste generated. It is still far from circular. Thus, transitions in the industry itself and in our interaction with products are necessary. The question that arises is: how can the transition to circular plastic manufacturing in the Rotterdam maritime region contribute to a more sustainable, resilient and just economy?

Theory on transition management and socio-technical systems, analyses of spatial use and networks of the plastics industry in South Holland, and research on the developments in plastic manufacturing, has led to the understanding of the current networks and flows in the plastics industry. A subsequent analysis of stakeholders, policies and design options has led to a vision and strategy for the South Holland region, on how to shape a new circular plastics economy.

In the proposed strategy of Plasticity, (1) the strength of a strategic location in the port of Rotterdam is used to expand the renewable cycle of the bioplastics industry, and (2) by actively engaging citizens in reusing and recycling plastic products on a local level in the whole region, a technical circular cycle is enhanced in the whole province. Plastic is used as an example to demonstrate the contemporary issues around dependency on fossil material in the South Holland context, but similar principles regarding integrating the biological and technical cycle, facilitating space for innovation and growth of circular models, and engaging the whole socio-technical system in the transition process can be applied to other sectors and places. This expands the applicability of this vision and strategy beyond plastic.