The Dutch government is aiming to transition towards a fully circular economy by 2050 to mitigate climate change. To comply with these standards, a transition team for the construction sector has identified biobased materials as a cornerstone for the sector to become circular, enabling a crucial shift because of the sector's large contribution to carbon emissions and environmental pollution. Principles on which this shift relies are focused on environmental health while neglecting human wellbeing, especially mental health as one of the building blocks of human wellbeing (the other being physical health), albeit of great importance due to the significant amount of time humans spend indoors. Mental health is defined by life satisfaction and happiness and is measured through perception and experience. A two-way path is identified: from mental and physical health to human wellbeing. This research aims at identifying the effect of biobased insulation materials on the wellbeing of residents through a pilot study in the Netherlands. Individuals' perceptions and experiences of their living environments—specifically, their homes—serve as the basis for measuring wellbeing in this context. A mixed method is used, combining quantitative and qualitative results from a discrete choice experiment in a virtual reality environment. Participants were presented with three sets of two predetermined configurations. For every set, participants were asked to make a discrete choice between the two alternatives. The results were analysed using a Cox proportional hazard model in SPSS. The quantitative and qualitative data showed several discrepancies, but both emphasised the importance of indoor comfort. It is concluded that biobased insulation materials that ensure good indoor comfort are preferred over materials that don’t. Additionally, the importance of low maintenance needs and a small wall diameter is emphasised to lead to a preferred living environment and thus increased wellbeing. Recommendations to move the model beyond a pilot include diversifying the sample population, materials, and attributes that are presented while aligning these with the target audience, including non-expert views throughout the development of the model, and revealing associations with the materials.

GIS bottom-up analysis of the material stock of construction materials (concrete, bricks, mortar) in buildings in Brno, Czech Republic.

The growing world population gaining affluence is driving the extraction of raw materials. Resource availability is finite and concerns about future supply shortages rise. An approach to tackle this problem is circular economy which entails multiple strategies to reduce the demand of virgin materials. The implementation of those strategies require knowledge about material stocks and flows in a society. Material Flow Analysis can provide those insights. This fast developing field brought about MaTrace models which allow to trace the fate of materials in an open-loop recycling system. Recycling is only one of multiple circular strategies, thus the purpose of this research is to integrate an elaborate reuse model into a MaTrace model to build the foundation of a model which considers multiple circular strategies in sufficient ways. Two existing models were combined to achieve this: Consumer goods present in the MaTrace model were redirected into a reuse model and the end of life products of the reuse model were fed back into the MaTrace model. The impacts of this model extension were investigated by comparing the total in-use stock when considering one, two, and three consumer products' use cycles. Furthermore, Monte Carlo simulations were conducted to gain an understanding of the model behaviour. The results show that the total in-use stock increases in the peak by 8 % when reuse is considered. However, the gross stock dynamics do not change significantly in comparison to the original model. The evaluation of the Monte Carlo simulations revealed that the input which contributes the most uncertainty to the total in-use stock is the split of the initial material inflow. Furthermore, the results of the Monte Carlo simulations appear to be strongly connected to the initial input data. On the basis of this research it can be recommended to further extend MaTrace models to obtain a more comprehensive representation of a circular economy. Furthermore, MaTrace models using time series data for inflows and model parameter have to be created, this way MaTrace models can follow the evolution of MFA from static to dynamic models.

This research delves into the challenging task of exploring secondary materials supply from existing building stocks, crucial for sustainable resource management in the face of climate change. Focused on Hamburg, Germany, the study employs a unique combination of GIS-based bottom-up building stock analysis and dynamic Material Flow Analysis (dMFA) at the individual building level. Unlike previous studies, this approach specifically explores the dynamics of single buildings based on their unique characteristics, such as function and building age. The research explores the question of to what extent Hamburg’s construction sector can meet its material demand for stock maintenance through secondary materials until 2075. The study emphasizes the often-overlooked impact of regional and local dynamics, making Hamburg an ideal case study. The city’s lack of policies regarding primary material consumption in construction adds relevance to the investigation. By addressing five sub-research questions, the study comprehensively examines current material stocks, future outflows caused by demolition and renovation, future inflows for maintenance of the building stock and replacement construction, and the secondary material potential of outflows. The methodology involves quantifying material masses through GIS analysis and the application of material intensities for different building types and age cohorts. The obtained results feed into the dynamic MFA model. Recommendations arising from the findings include preparing for efficient brick recycling, developing storage concepts for secondary materials based on the determined spatio-temporal characteristics of outflows and initiating policy discussions on reducing primary material consumption in construction. This research not only contributes to the field of Industrial Ecology by extending the methodology for material stock and flow research on the local level but also has practical implications. Stakeholders in Hamburg, including policymakers, urban planners, and waste operators, can leverage the developed methodologies and results for informed decision-making. The study provides a blueprint for future research in other urban regions, showcasing the potential of openly available cadastre data and emphasizing the importance of addressing the complexities of material flows at a granular level.

Modular Floating Structures (MFS) have emerged as an innovative alternative for sustainable offshore urban development, providing a response to the multifaceted challenges posed by coastal urban expansion: significant urban growth and coastal migration, increasing sea-level rise exposure and land scarcity. This thesis presents a geographically oriented exploration of the global technical and motivation potential of MFS – in maximum achievable suitable area, offshore population and material demand -, integrating technical, environmental, and demographic factors through a comprehensive GIS analysis. The methodology of this analysis involves the following key steps: 1) Establishing the Service Limit State (SLS) technical potential map by considering the natural constraints bathymetry, average wave energy, average wind speed, and hurricane risk; 2) establishing the Ultimate Limit State (ULS) technical potential map based on the SLS map and the extreme value constraints 100-year return significant wave height and 100-year return wind velocity; 3) establishing the ocean planning technical potential based on the ULS map and integrating the ocean planning constraints marine protected areas and shipping routes; 4) establishing the motivation potential maps, which are based on the outcomes of steps 1, 2, and 3 and the proximity to a coastal city as a key motivation factor; 5) evaluating additional motivation layers to reveal where potential driving forces are for floating urban development within local contexts. The maps lead to first estimates of maximum suitable area and offshore population, guiding calculations for required materials in floating breakwaters, proposed as reused end-of-life (EOL) ships, and MFS substructures. This thesis uncovers several insights. The use of Geographical Information Systems (GIS) in this field enables the exploration of the technical potential of offshore urban development, offering first estimations for total area, offshore population, and material use (specifically EOL ships and steel). On a global scale, about 84000 km2 are suitable for MFS implementation, potentially accommodating up to 1.6 billion people. These results demonstrate the potential to contribute significantly to climate-adaptive housing capacity. If the entire technical potential were to be realized the global demand for EOL ships would be approximately 261000, a demand significantly exceeding the current in-use global merchant fleet by nearly threefold. The global steel demand for the construction of the MFS substructures would be 26 billion tons, a vast amount that exceeds the annual global steel demand by about 20 times. These vast numbers may significantly impact the ship-breaking industry and global steel flows. These insights provide valuable perspectives on MFS implementation, holding the potential to significantly contribute to climate-adaptive housing capacity, however raising critical questions about sustainable material consumption and production. This research unfolds new possibilities in the field of sustainable offshore urban development and serves as a launchpad for further large scale exploration and analysis in this dynamic area of research. Future research could further assess the sustainability of offshore urban development, building upon the findings of this thesis. Potential areas of investigation include for example comparing material requirements for MFS substructures to those of land-based building substructures or conducting micro, meso or macro-scale scenario-based Material Flow Analysis (MFA) to evaluate the influence on the global steel flow and ship-breaking industry, using the technical potential estimates presented in this thesis on local and global scale as a foundational reference.

With growing demand for energy and the shift towards renewable energy, countries like India are targeting energy mixture with alternate sources like solar, wind and water. With the current growth of solar energy use in India, it is predicted that high amounts of Solar Photovoltaic (PV) waste would be generated in the near future which left improperly managed would lead high amount of useful and expensive material ending up in landfills. This research focuses on the potential material generated from the growth of solar PV stock in India. This research studied the growth of solar PV industry and the spread of Solar PV growth in India. The stock growth of solar PV till 2030 based on India’s renewable energy goal of 280 GW solar energy is taken. Further study on End of Life (EOL) management of Solar PV was studied and the best practice scenarios from around the globe for handling Solar PV waste was studied. The circular economy approach for the Solar PV industry was also reviewed. 3 scenarios were created to determine how the waste from these Solar PV would be managed based on the current state in India, using best-case scenario from around the world and circular economy practices. These scenarios were simulated using dynamic material flow analysis to determine the waste inflow and outflow of material based on the defined scenario. It was determined that more than 21 million tonnes of waste would end up in landfill by 2060 if India does not increase its recycling capabilities. Also, by adapting Germany’s WEEE regulation for solar PV waste management, 2 other scenarios are created, which uses extended producer responsibility and would provide India with the capability to handle future Solar PV waste. A comparison of these 2 scenarios showed higher recovery of material in one (423 thousand tonnes) while generating 21 times more waste to landfill than the other (16 thousand tonnes). It is found that the outflow of tonnes of material is same in all 3 of the scenarios and the highest amount of waste produced by the 280GW target of 2030 would be in 2055 at over 1.6 million tonnes. It is predicted that landfill can end by 2033 or 2044 in the defined scenarios but shows variation in the amount of recovered material would differ between them. Achieving the scenarios put forward would involve coordination between Government agencies, producers of solar PV and the actual users of PVs. A shift to a formal waste management sector would be required and a successful implementation of policies and targets would lead to improvement in multiple Sustainable Development Goals (SDG) for India.

Transitioning of energy intensive industries (EIIs) towards more sustainability forms an important building block in achieving the Paris climate goals. Silicon carbide (SiC) production is such an EII, though it has not yet received much attention in systemic research. This thesis attempts to fill this gap by studying how SiC flows through the global economy. The objectives are to describe the SiC supply chain, quantify its flows and analyse the supply chain’s resilience. Findings: The global SiC production capacity constitutes 1 000 000 t per year. With 55.34% the Asia Pacific region is the biggest producer, followed by Europe with 32.7%, rest of world with 7.96% and North America with 4%. In order of quantity, abrasives, metallurgy, refractories, technical ceramics, other industrial uses, semiconductors and jewellery are the main applications of SiC. Around 5% of the material is recycled (USGS, 2021). High energy requirements in SiC production, as well as strict emission regulations are identified as the main supply risks. Substitution, use reduction, recycling and stockpiling can only minimally absorb supply disturbances at their current state. However, recycling is currently a popular topic in the industry and under development. In the mid-term, recycling activities might become a way to increase supply chain resilience. Another strategy that could lower pressure on the supply chain is using SiC production to balance the energy grid. That is, to produce when there is an oversupply of energy and to halt production when there is a shortcoming. Implications: This thesis shows that sustainability efforts in the SiC industry are not only environmentally desirable, but might also add to its supply chain’s resilience. The case of SiC shows that small EIIs that have so far not received much attention can offer high returns in terms of knowledge gained.

Concrete is one of the most widely used materials in residential building construction. It contributes about 4% to 7% of global greenhouse gas emissions annually. Thus, better understanding the material stocks and flows of concrete can support efforts to better manage this resource and its use. Concrete is especially popular for the construction of building foundations. Previous research has shown that foundations can account for 25% to 60% of residential housing mass. Despite this, no in-depth analysis of material requirements of foundations has been conducted. Foundation design depends on the housing type and soil type. Considering foundations’ substantial share of building mass, I analyze them in this thesis in the form of a case study of residential housing built in Trondheim between 2010 and 2020. To account for all emissions from cradle-to-construction site I also compare the concrete production emissions to the last-leg transport emissions. The residential building foundations’ material requirements were estimated with a model I specifically developed for this thesis. 507 000 tonnes of concrete were used from 2010 to 2020 to build residential building foundations in Trondheim. The results show that the concrete production emissions represent 99% and the last-leg transport emissions 1% of the total cradle-to-construction site emissions. The average material intensity coefficient across all buildings in Trondheim is 402 kg of concrete in the foundation per one m2 useful floor area. I disaggregated the buildings into five types: single family house, semi-detached house, rowhouse, apartment building, assisted & communal living. When disaggregated, the building types’ material intensities vary, on average, 8% around 402 kg/m2 useful floor area. The largest difference being 20% below the mean. As a result, there are no substantial differences of material requirements per m2 useful floor area between different building types. However, building on peat and bog soils increases the material requirements by 80% compared to all other soil types found in Trondheim. This is due to the low bearing capacity of peat and bog soils. Trondheim currently plans its residential zoning until 2034. 5% of the planned zones are located on peat and bog. A rough estimate suggests that up to 380 000 tonnes of carbon could be stored in the affected peat and bog areas, which could be released as construction on this land begins. Together with the 80% increased material requirements of foundations on peat and bog, this can cause a lot of emissions. As a result, my short-term recommendation is that these areas are either preserved as nature reserves or only light structures that do not need a foundation are constructed. In the long-term I recommend that new zoning types for city planning are developed that take soil types into account. Lastly, the effects of soil types should be taken into account in future studies of the material stock in residential housing. Feel free to contact the author for more information and the supporting information.