Provision of housing services within planetary limits: A methodological framework for the urban circular economy

The provision of decent housing for all is a core sustainable development goal (SDG) and a fundamental human right. However, the construction sector is the world's largest consumer of raw materials, and 40% of global CO2 emissions are attributed to housing and construction. The challenge of providing decarbonised and decent housing differs per urbanisation context. In rapidly developing cities, there is the question of how to build decent, affordable housing that meets human needs without locking the city in resource dependency and negative climate impacts. In aging cities, there is the question of how to reduce the emissions and material use of old building stock. The circular economy proposes strategies to close material loops, minimize harmful resource use and cease local waste generation. However, meeting housing needs within climate targets requires consideration of more than material and energy stocks and flows. There is a paucity of attention for social dimensions and clear targets in monitoring the circular economy. We propose a methodological framework to articulate the provision of housing services within planetary boundaries by implementing circular economy strategies. It consists of four elements. First, the material system of stocks and flows. The stock characteristics relevant to the provision of housing are building typologies, their related materials, age, area and height. The relevant flows are construction materials, operational energy, demolition materials, and direct emissions. The material system can be modelled and analysed using material flow analysis. Second, the social system that influences and is influenced by the construction, operation and demolition of buildings. The social system consists of agents, their actions, and the structural factors that act on them. Agents are actors related to each stock and flow. Agents relevant to the provision of housing are architects, constructors, clients, developers, etc. Structural factors draw on Gidden’s structuration theory, and are made up of rules and resources such as building codes, cultural norms and power relations. Actions are the circular economy practices that the agents choose to do: repair, renovate, re-use, recycle. The social system is analysed with structural analysis using data from interviews, surveys and/or workshops. Third, the material system and social system act together in the provision of services related to housing: living space (m2), warmth (RC in m2K/W), access to amenities (amenities/km2), etc. These are elicited based on the analysis of the material and social system. Fourth, the assessment of the housing system’s ability to meet needs within planetary boundaries. The services required to fulfil the provision of housing are not universal; they depend on the needs of the actors. A dwelling may fulfil one or many needs: e.g. security of tenure, affordability, habitability, location, cultural adequacy, etc. Furthermore, the provision of services has consequences for the ability to stay within planetary boundaries: which may be defined in relation to climate targets, biosphere integrity, land-use change, etc. This is monitored with the use of biophysical indicators (i.e. carbon and material footprint) and well-being indicators, using life cycle inventory and survey data. In conclusion, the proposed methodological framework builds upon Industrial Ecology and circular economy scholarship, and complements it with social consideration to respond to the central and urgent question: how to provide decent housing within planetary boundaries.