A tool that contributes to solving the cultural barrier of the lack of knowlegde about circularity in conventional members of project teams. Using three case studies an evaluation tool is developed. With gathering circular project dynamics, validating them and integrating them into the evaluation tool. The tool intends to help members of project teams to learn about the integration of project dynamics for circularity in construction projects to stimulate the realization of circular ambitions. But also intends to stimulate organizational level learning to benefit the transition towards circular economy.

This thesis focuses on the collaboration of two innovative materials - Fibre Reinforced Polymers (FRP) and structural glass – in the design of a (hybrid) footbridge with a 30 meter span. The choice of subject is led by a rising popularity of these materials in bridge design and strengthened by positive recent developments in conceptual small-scale FRP & glass hybrid structures. This research will try to take previous research one step further and will combine the advantages of both materials to reach a structurally efficient bridge design. The research question is as follows: “Can a hybrid pedestrian bridge with a loadbearing structure of FRP and structural glass be designed while making optimal use of the material properties of both materials?”. The design by research process is divided in multiple steps. First of all a theoretical framework is created, with state-of-the-art information about the material properties of glass and FRP. This theoretical framework resulted - via design rules - in several preliminary design variants of which the structurally most efficient, most transparent and safest variant is chosen and subsequently elaborated on. The chosen variant is optimized by using a form-finding and geometric optimization process powered by the Grasshopper plugin Kangaroo and Finite Element software DIANA. The research shows - via its design rules – that a hybrid facetted shell bridge, consisting of glass facets and FRP joints is the most efficient variant. A concave shape is chosen for its “natural” parapet and relatively low share of bending stress in the total stress, while still measuring up to the bridges’ requirements. The concave shape is tessellated with triangular panels due to problems with the – in theory – more efficient hexagonal panels. By shortening the length of connections along each side of a triangular panel, the behavior of hexagonal panels is approximated. Several topologically different triangular tessellation variants have been analyzed using DIANA. The topological variant based on a combination of the equilateral and isosceles triangle proved to result in the lowest stress and deformation values under NEN-based loads and is therefore the most efficient variant. By adding more curvature to the base of the bridge, better shell behavior is achieved, resulting in even lower stress and deformation values. The connection between the panels is made using an FRP embedded sheet, which results in a higher axial stiffness and ultimately also a higher critical load of the bridge. The ideal thickness of this sheet is determined with FEM analysis. A clamped double-pin joint is chosen for its uniformity and adaptability. Finally, an uncertainty analysis is performed to investigate the influence of tolerance related production flaws on stress levels in the joint, which resulted in no issues.

In recent years, the housing market has been under pressure due to growing demand for (inner-city) housing and a lack of supply. Housing is in high demand as a result of factors such as population growth, rapid urbanization, smaller households, the freezing of "mobility in houses, and so on. The low developing speed to cater to these issues might instigate an investigation into possible adjustments to the current building methods to increase the rate of housing production. The building sector has the potential to fulfil these demands by becoming more product-driven, efficient and sustainable, which are said to be attainable with the use of modular construction (Bertham et al., 2019). However, traditionally, the building industry is characterized as a project-driven industry with unique characteristics such as location-bound design, one-of-a-kind/unique production, changing partnerships per project, outdoor and environmental factors, and multiple clients and suppliers involved in a single project. These characteristics conflict with the product-driven ambitions, leading to negative effects on performance such as low levels of effectiveness and efficiency, low rates of innovation and difficulties in knowledge sharing and learning. This research explores the potential benefits of vertical integration in modular construction value chains. The study is based on an empirical single case study of an integrated modular building company in the Netherlands. The case study examines the implementation of vertical integration in the modular building company, and its impact on the project- and product value chains. To achieve effective vertical value chain integration during the development phase, the industry needs to focus on synergy, competency, and organization and adopting the appropriate production system fitting to their organization, product and production profile. Synergy involves establishing a clear and structured collaboration structure between departments, early involvement of key parties, and having a systematic approach to the project. Competency involves having adequate experience in the modular construction industry, defining a modular design system with configurable designs, and focusing on modular design systems with configurable elements, design flexibility, and efficient and streamlined production processes. Organization involves establishing unambiguous guidelines and expectations for each phase of the project, creating a comprehensive project plan that clearly defines the roles and responsibilities of each team member, and identifying the primary coordinator for each phase. Additionally, it is essential to have a supportive and collaborative company culture with trust among employees, morale and motivation, and leadership that encourages and facilitates cooperation and collaboration across different departments and locations for all factors to thrive. Based on the modular construction goal, fitting product and production characteristics were explored, which resulted in defining appropriate production systems. The focus on modular design systems with configurable products and the need for design flexibility described in the product description align with the characteristics of assemble-to-order production. The emphasis on product-oriented and project-oriented approaches, as well as the need for design consistency and efficient translation to production, aligns with the characteristics of make-to-order production.

An alternative proposal for the densification needs of Gerji site in Addis Ababa, Ethiopia. The design itself is systematic and highly flexible, on a larger scale, it could be an example of a gentler way of deification that is caring for the people involved.

The number of raw materials consumed and waste generated by the construction industry is no longer a viable solution in the future. It is required for the construction industry to move from a linear towards a circular economy (CE) by circular construction (CC). The unfamiliarity in actions that need to be taken for CC is still new terrain for many companies since the whole life cycle of a project needs to be considered and is plagued with technical, legal and cost issues that obstruct CC. Contract forms such as Early Contractor Involvement (ECI) involve contractors in the design phase of a project, such as suppliers, builders, and demolition contractors, to engender a better design by sharing and creating new knowledge. There are, however, no sources directly indicating that the benefits of ECI also regard circularity. At the same time, issues that emerge with CC remain an obstacle for fully transitioning to a CE. This research aims to understand better the issues regarding CC and if ECI would be beneficial in solving them due to the knowledge contribution of contractors and their collaboration with other parties in the design process. Therefore the research question is framed as follows: “How is contractor’s knowledge contribution improving circular construction in ECI context?” The research consists of a literature study and an empirical study. First, the literature study was conducted to define the relevant concepts such as ECI, CC and knowledge processes. Next, to understand the knowledge contribution of contractors to CC in the design process, interviews with practitioners involved in CC projects were conducted according to the Critical Incident Technique (CIT). In CIT, research participants are asked to recall and describe a time when a behaviour, action, or occurrence impacted a specified outcome positively or negatively. From the empirical study, there can be concluded that contractors' knowledge contribution plays an essential role in the feasibility of a circular design solution. However, the dynamics in collaboration between multiple parties can lead to better circular results. Since the collaboration can result in knowledge creation and sharing, developing a good work relationship between contractor and client and problems can be jointly solved when there is mutual support. This, however, also requires trust and transparency between the parties, and if lacking, it can obstruct CC.

Being one of the world’s largest waste generator, the construction industry is responsible for a train of events such as global warming, climate change, and depletion of natural resources. Materials are exhausted globally to a large extent and the waste produced in the process is not treated properly. A “take-make-dispose” or popularly known as linear economy is the process that is adopted to treat the waste currently, where large quantities of resources end up as waste after demolition of the building. This grabs our attention towards the concept of Circular Economy (CE) with the goal to potentially minimize the pending issues arising from the construction sector through recirculation of building materials. However, due to the unfamiliarity of its economic feasibility, many are still reluctant for investing in circularity as they believe circular construction to be more expensive. The main challenge is to overcome the lack of understanding of the available circular strategies and their effect on their business. Therefore, the objective of this research is to investigate how buildings can be made more circular. Furthermore, the aim is to compare the alternatives based on the life cycle costs and a circularity measure, so that stakeholders are in a better position to invest/favor circularity in general. Finally, the objective is to present a way to invest in circular projects by merging the methods used in this study. Firstly, literature review was conducted to develop a better understanding of the most important concepts in relation to this research. It reveals the need for several methods to conduct the research, and hence three methods are further elaborated. An inventory of possible circular interventions was made and categorized based on strategies and layers of the building. The methods discussed were applied to a case study. The application of interventions on the base case intends to gradually increase the circularity of the building. This gradual increase in circularity calls for a comparison of a traditional building with its circular twin. Based on the analysis, it can be concluded that a comparison as such can help in a parallel tracking of both circularity level and life cycle costs of a building, which in turn aids in taking both the factors into account for decision making. Thus, both the costs and circularity of a building are quantified. The main findings are: A building can be made more circular by searching for circular activities that can replace a non-circular activity by using a circular strategy framework- in this case, R-strategy was used. The application of circular activities or interventions can be categorized layer-wise to carefully examine the impact of the activity on the circulatory level and costs associated with the building. This can be done by diving the building into different layers- in this case, Stewart Brand layers was used. The circularity of the building is to be increased gradually. Further, several alternatives can be generated to analyze the best-case scenario that can justify both the circularity and cost of a building. This is done by using a circularity measure and life cycle costing- in this case, material circularity index and discounted cash flow analysis were used respectively. Finally, the results can be analyzed by quantifying both circularity and cost. This makes sure circularity in a building is not compromised for the costs associated with the building. This way, stakeholders are better aware of the opportunities and can make better decisions in selecting circular projects which could lead to enhance the acceptance of circularity within the building sector.

Addis Ababa is a city experiencing a huge population boom, and where the vast majority of housing can be classified as “slum”. State-owned kebele housing, which houses an estimated 40% of the city’s inhabitants, has very low rents but is not maintained, leading to deterioration. Thus, the city is left with a severe shortage of adequate housing. Current state-led developments intended to alleviate the acute housing problem do not address the specific situation of Addis Ababa, and do not allow for the flexibility and adaptability that is required by residents. This research and design project focusses on a specific site in Gerji, owned by the Federal Housing Corporation, and proposes a new model for mid-density, low-rise development which is specific to the context of Ethiopia and suitable for the varying and different living patterns of people in Addis Ababa. The project includes ethnographic research, looking into the lifestyles and daily habits of local residents, as well as documenting their homes and living spaces. Further research was conducted into vernacular and historical building styles and construction methods present in Ethiopia, which was used to inform the design and better understand the specific context of Ethiopia. The research concluded that many different living patterns must be accommodated in a new development, and that this should allow for flexibility and adaptability as household incomes and expectations change over time. Moreover, homes should be suitable for the climate and materials and construction techniques should be informed by local customs in order to aid social sustainability. Finally, tenure options, functions and typologies should be mixed to create a diverse and resilient neighbourhood. The proposed design addresses the research by offering three distinct typologies of building, all of which offer the flexibility needed to allow for different functions and uses. These three typologies are aimed at different sectors of the community and are proposed to be offered in different tenure models. The design is simple and uses adobe bricks and laminated bamboo lumber as its main construction materials. These both use raw materials that can easily be sourced locally and can be processed cheaply on site, using local labour. Ultimately, the proposal achieves a density similar to that of local state-funded housing developments, known as “condominiums”, suggesting that this more varied and site-specific approach to tackling the housing shortage is feasible for Addis Ababa. Adopting such an approach, which looks to local customs and vernacular styles for inspiration, is a radical alternative to the unsustainable route currently being taken in Addis Ababa.

In the built environment, the continuous growth and expansion of urban areas worldwide have become alarming. The built environment is continuously developing in an unsustainable manner, and in the mid-term future, resources will be scarce if practices are not changed. Therefore, new building materials and methods need to be implemented to mitigate the substantial problem and prevent a point of no return. This research focuses on the Global South taking Kenya as a single case study to investigate the following research question: How can NGOs support local stakeholders in Kenya to shift the production of affordable housing by the use of circular materials and methods? This research design was conducted through a double-diamond framework, and data was collected in a qualitative manner. The objective is to understand housing practices in the local market to seek alternatives to shift affordable housing development into circular practices. By these means, this research attempts to provide information on the processes of support that NGOs can give to implement circular materials and methods in housing, strategies to create acceptance and adaptation of these materials in the local market and the ways to create economic and social value through circularity in the built environment. A comprehensive literature review was made to develop a foundation of knowledge for the empirical study. Furthermore, as a result of the empirical study and the triangulation of data between the literature review and the research findings, a guideline for NGOs to help local stakeholders shift to circularity was created. The output of this study endeavours to develop an understanding of how the demand and the supply of circular materials and methods need to be tackled to be able to disseminate circularity in the local built environment and create the shift towards the use of these innovations and new building practices. As a result, the depletion of natural resources and the amount of CO2 emissions produced by the built environment in Kenya can be controlled while providing affordable and adequate housing for the country.

The built environment has a huge contribution to the total CO2 and waste production, due to their linear approach of “take, make & dispose”. A shift in construction is needed towards the circular economy to close material loops, decrease and eventually stop the depletion of the earth’s resources. The construction project organisation could be an important vehicle for this transition. The construction project organisation is made up of all actors who, together, realise a project. The outcome of a project is the result of the collaborations, interactions and partner networks within a construction project organisation. Organising these interactions in another way could result in a more effective approach towards the circular economy. The demand for circular projects is increasing and despite this increase in demand, the construction project organisations still approach new types of projects in a linear way. Governments are speeding up this process, by creating regulations, incentives, and deadlines for all industries. The built environment has to change their way of working to commit to these new standards in the future. Product-service systems is a concept which could contribute to this transition in the built environment and reduce the depletion of resources. Consumers will pay for project-use and the producer will maintain ownership which stimulates sustainability. To accomplish this in the built environment and increase project value, construction project organisations have to change their traditional structures and develop new partner networks. The following research question will address this problem: How can construction project organisations change towards the Circular Economy and add value by implementing Product-Service Systems? The purpose of this research is to fill the gap between theory and practice. This is done by restructuring the stakeholder network of a construction project organisation, to meet the circular demand, by implementing the concept of product-service systems. The aim is to get a better understanding of the current state of construction project organisations and how they could implement product-service systems more effectively.

The circular economy is an economic model in which resources are circulated in a closed loop by adopting the R-strategies (e.g. reuse, recycling, and reduce) to minimize waste and pollution. Repurposing vacant buildings, known as adaptive reuse, is in line with the principle of circular economy, as it contributes to the reuse of the built assets instead of their demolition. In addition, this can help to conserve resources and reduce the environmental impact of building construction. Furthermore, adaptive reuse is not only necessary for vacant properties but also for obsolete buildings. Thus, it is an unavoidable practice in the built environment. This implies that adaptability should be incorporated into this kind of projects besides circularity. However, recent research revealed that many of the Dutch adaptive reuse projects were implemented without adequate consideration of circular solutions. Accordingly, this research project aims to develop practical guidelines that could guide practitioners on operationalizing circularity and adaptability in the adaptive reuse of vacant and obsolete real estate. Sequentially, three approaches with different research methods were followed to answer the main research question: ‘’How can circularity and adaptability be promoted in the reuse of vacant and obsolete real estate?’’ The first approach is the documentation of existing knowledge. This approach was followed to answer the first sub-question: ‘’What are the criteria and measures for reusing obsolete and vacant buildings in a circular and adaptable manner?’’ In this approach, a literature review was carried out. The literature review led to the identification of 12 criteria and 8 measures for circular and adaptable adaptive reuse. The second approach is case studies on circular adaptive reuse projects of vacant and obsolete buildings. This approach was followed to answer the second sub-question: ‘’To what extent are circularity- and adaptability-related measures implemented in reusing vacant and obsolete buildings?’’ In this approach, three research methods were used in two case studies, namely: archival research, interviews, and field observation were used simultaneously. The findings of the cross-case analysis of two case studies resulted in adding 8 measures to the previously defined measures from the literature, totaling 16 measures. The third approach is the formulation and validation of guidelines based on knowledge gained from theory and practice. This approach was followed to answer the third sub-question: ‘’How can guidelines guide professionals on how to promote circularity and adaptability-related measures in the reuse of vacant and obsolete buildings?’.’ In this approach, the guidelines were synthesized based on knowledge gained from the literature and findings of the two case studies. The results of developing and validating the guidelines contributed to adopting 13 guidelines. Overall, the validation outcomes indicate that the guidelines are informative and useful when visualized. However, they need to be updated constantly for their applicability in practice.

The aim of this research was to investigate the effects of implementing circularity in infrastructural construction projects. As a very polluting sector, circularity is becoming a more and more popular theme in the construction industry. Driven by both governmental regulations of reaching a full circular economy in 2050 and intrinsic motivation, construction companies are slowly introducing practices which contribute to circularity. Unfortunately, not much is yet known about the effects on project process and construction costs when implementing circularity. This research has initiated the first step towards understanding what the effects of circularity are on infrastructural construction projects, providing welcoming insights to both the academic world and practice. Based on a case specific comparison, a circular construction project is more expensive than a regular construction project, due to extra activities which need to be executed before a secondhand material can be applied. Regarding the project process, the circular construction project introduced ''gathering of materials'' as a whole new process step which is constantly interchanging with (re)design until a final design has been completed.

The increasing significance of the circular economy in the real estate construction industry is driven by evolving environmental, social, political, and economic factors. While there is increasing pressure for a national transition to a circular building economy, the sector continues to confront numerous challenges, risks, and uncertainties. To promote pro-circular decision-making among project management stakeholders, this research investigates how incentives need to be implemented in order to be an effective strategy to encourage project management stakeholders in making pro circular project decisions. During the research an overall research strategy, the systemic design toolkit, has been used. This method integrates systems thinking with a human-centered, multi-stakeholder focus, by addressing the intricate social, economic, and environmental aspects of the issue at hand. The study comprises two sections: a theoretical segment employing quantitative research and an empirical segment employing qualitative research. The theoretical phase explores the interorganizational dynamics that influence circular decision-making, delves into the roles and perspectives of project management stakeholders, and examines the concept of incentives. The empirical phase starts with semi-structured interviews to gain insights into the behavior, intentions, interrelationships, interests, and influence of relevant actors involved in decision-making processes. Subsequently, unstructured brainstorming and validation interviews are conducted to identify and develop effective incentives within the financial, social, and moral clusters. The research findings provide empirical evidence that incentives can serve as a viable strategy for motivating project management stakeholders to make pro-circular strategic project decisions. These incentives are integrated into a comprehensive incentive scheme, outlined in the concluding section of the findings. Through the adoption of these incentives, stakeholders can be effectively motivated to embrace circular principles and actively contribute to the establishment of a circular building economy. Additionally, some key variables have been identified as influential factors in the success of the incentives: the involvement of supplying stakeholders and the targeted audience, as well as a thorough understanding of the rationale behind circular project rejection, the prevailing power dynamics, and the degree of stakeholder involvement throughout the various design phases.

Economies, society, and organizations are operating on borrowed time (Lacy & Rutqvist, 2015). As a response to urgent planetary and societal needs, a critical shift is required on every aspect of how organizations in the construction sector, one of the most resource intensive and pollutant industries, propose, create, and capture value (Bocken & Antikainen, 2019). The circular economy (CE) has been embraced in the architectural discourse as one of the most powerful, innovative, and viable business strategies to achieve sustainability in the built environment. However, architectural firms are still struggling to translate the concept into their business models (BMs) (Urbinati et al., 2017; Accenture, 2014; Khan et al., 2020). Scholars argue that in order for firms to reorganize their strategies, resources, and structures to those that are free from linear constraints, new dynamic organizational capabilities (particular kills, processes, and organizational activities) are required (Lacy & Rutqvist, 2015; Khan et al., 2020; Bauwens et al., 2020). However, most research on the subject has been developed from a practice-oriented perspective and/or has been primarily focused on large profit-driven organizations, rather than smaller creative firms driven by strategic goals beyond financial revenues (Lu & Sexton, 2006; Bos-de Vos et al., 2017). Through semi-structured interviews and qualitative data collection with stakeholders in four architectural firms operating in the Netherlands; the research addresses the limited academical research on this field by exploring the Dynamic Capability Approach of the firm as a BM transformation know-how strategy in favor of CE. The findings indicate that the dynamic capabilities approach is undeniably beneficial for CE implementation among architectural firms. In this regard, the research identifies 15 microfoundations of sense, seize, and reconfigure dynamic capabilities that architects and entrepreneurs can implement to transform the way they create, deliver and capture value. Furthermore, this thesis concludes that architectural firms operate on the basis of a BM portfolio with CE embedded at the project-based level. Finally, the findings suggest that CE has had limited impact in the value proposition of architects but has increased the complexity of their value creations and delivery components, ultimately leading to trade-offs and creative strategies to capture value and ensure the firms survival in still transitionary markets.

The goal of the graduation studio is to research and design housing solutions that improve the livelihood of Addis Ababa’s urban dwellers. Combining analysis, planning and design, the participants of this graduation studio were challenged to use multidisciplinary research methods and tools to elaborate design proposals for the development of a pilot housing project in Addis Ababa. Ethiopia is following the urbanization trend which can be seen across Africa. This is reflected in the population growth in Addis Ababa which has doubled from 2.3million in 2000, to 4.5million in 2020. The primary reasons for this rural-to-urban migration are education and work. We find that unmonitored overcrowded households, long commuting distances and high urban expenses pose obstacles to the progress of all Ethiopian students. This project places due importance on arriving students, as I believe that acknowledging this group as critical to the future development of Addis Ababa and Ethiopia as a whole.”

The purpose of this master thesis is to gather information from current practices and make recommendations to facilitate implementation of circularity in the building process. The past years, circularity has become a popular term in the built environment. This approach prefers a more circular way of perceiving the building process. Literature indicates that implementation of circularity in the building process, probably, will require different actors to be involved and different decisions to be made. The following research question is proposed: “Which actors should be involved (in the beginning of the building process) to ensure circularity (implementation of circular building) throughout all phases in the building process and which actors should influence decision-making?” The following research method is adopted: a literature study, and case study research including interviews. From this literature study, assessment criteria for the case study research can be conducted. The case study research evaluates the actor network and decision-making processes based on three building projects. These projects are: Townhall in Brummen by RAU built in 2013; The Green House in Utrecht by cepezed built in 2018; and EDGE Olympic in Amsterdam by Architekten Cie. built in 2018. This thesis concludes that circular-related actors and traditional actors with circular-related resources should be involved and be influential in decision-making in the building process of circular building projects. This study particularly demonstrates the benefit of early on involvement of the following circular-related actors: transformation agent, circularity expert, reclamation expert, dismantler, and legal officer. In order to increase their influence on decision-making these actors should become part of the project team, or at least be taken seriously and offered room to influence decision-making. Especially, if traditional actors lack knowledge and resources for implementing circularity. Moreover, contribution of their resources to implement circularity is facilitated, if these actors are involved early on. Early on decision-making on circularity, particularly for long-lived layers (in comparison to short-lived layers), is beneficial for its implementation in practice. Later on in the building process, after the initiation and preparation (and design) phase, implementation is difficult.

The pioneers in the early 21th century who built the first big offshore wind farms now have to compete with the quickly improving renewable energy technologies and see their farm being out-dated (See also: Dvorak, 2013 & Wind Energy Update, 2013). At present, wind farm owners face difficult decisions when finding the right O&M contract for their offshore wind farm after the warranty period with the original equipment manufacturer (OEM) has ended. Because of a lack of experience in this new O&M phase, decision-making processes are not yet structured or standardized. During the warranty period of approximately 5-10 years, traditional performance-based contracts based on availability guarantees are offered by the turbine manufacturer. To stimulate innovation and increase the energy output, some O&M activities may be better off outside the scope of the performance contract and need a different sourcing scenario. This leads to the aim of this research to compose a decision-making flowchart that can be used when finding a new sourcing strategy for the O&M of offshore wind farms in the post-warranty future. It was concluded that these O&M activities can be segmented in three main items: the offshore turbine maintenance activities, offshore logistics and the onshore back-office maintenance operations. Increasing the maintenance efforts will improve the overall availability of the wind farm but will also increase the required resources to be devoted to O&M. For this reason, it is important to know the cost-drivers for the main O&M activities (Milborrow, 2010). Insights in these costs-drivers and performance shapers were combined and used as input for the decision-making tool. Next, three decision-making variables were derived from the Transaction cost theory and Agency theory that structures the outsourcing decision including the type of contract. First, the owners’ techniques and processes that are needed to transfer or take in-house a good or service were identified as the ‘proprietary nature’ which is an important decision variable when choosing between the O&M in-house or outsource option. Secondly, when outsourcing with a performance-based contract, a relatively high level of knowability of the performance is required compared to behaviour-based contracts. Thirdly, it was found that the type of contract is influenced by the dynamics of the environment because if the performance requirements change due to new innovations, the performance outcome becomes difficult to measure. The three decision-making options altogether lead to four scenarios that could offer a possible sourcing strategy after the warranty period: The Broker scenario, The Incubator scenario, The Coordinator scenario and The Controller scenario. The decision-making flowchart and the four post-warranty sourcing scenarios contribute to a more efficient scoping of the current performance-based maintenance contract in the post warranty future, so that O&M costs can be minimized while keeping the performance high.

The Linear Economy currently follows the Take - Make – Dispose model. This paradigm is based on the consumption of resources rather than the preservation of their value. If this model remains dominant, it will lead to material scarcity, thereby increasing materials prices. The linear economy has a negative effect on nature as this model creates a tremendous amount of waste. Minimising the waste, maximising the value and facilitating the reuse of materials is the foundation of the Circular Economy. Lack of information regarding materials is recognised as one of the primary causes for waste generation. As a result, material passports were created to facilitate information sharing. However, some barriers hinder the application of these material passports. This research analysed the barriers and requirements of material passports and whether these barriers can be addressed through the characteristics of Blockchain technology such as transparency, distributive nature and security. However, a traditional blockchain has its challenges, such as scalability and an unsustainable consensus mechanism. In this research, a conceptual framework of Hyperledger Fabric (Private-permissioned Blockchain) based material passports is developed to tackle these barriers and meet the requirements. The framework developed aims to be helpful to create Hyperledger Fabric-based Material Passport by Material Passport Developers. Additionally, this helps the stakeholders within the built environment to understand the working of Blockchain-based material passports. The framework's validation was carried out by developing two scenarios, i.e., the Blockchain-based material passport and the BIM-based material passport and comparing them. This step was carried out to see whether the proposed Blockchain-based Material Passport framework will address the barriers of BIM-based material passports. In addition, semi-structured interviews with different stakeholders who use material passports to validate the framework.

The transition towards a circular economy has many barriers. Scholars have researched these barriers in the last few years, though due to lack of implemented cases, practical insights are missing. With a holistic overview, this research connects the theoretical knowledge with insights gained from practice. New insights can be found by looking at the barriers and enablers identified when implementing a product-as-a-service within the Dutch built environment. With the research question “How to overcome the barriers with respect to financial, legal and organisational aspects of implementing a product-as-a-service business model within the Dutch built environment”, this research will provide essential insights for a more successful and accurate implementation of product-as-a-service in the future. With the use of multiple cases, the barriers and enablers identified in practice are studied. By combining the barriers and enablers of both perspectives into one list, an overview is created. The gathered findings are analysed according to; the times mentioned, relations between barriers and enablers and the relation between theory and practice. Through a compressed overview, of the most common barriers and the most effective enablers, a ranking is given by experts based on their importance. Based on this research, two ways support the primary research aim. First, the identification of barriers, and secondly, the correct enabler should be chosen to overcome the barrier, through the various overviews provided in the research. To be mentioned is the input given; which is to be used as an indication and helps to overcome the barriers, rather than completely solving the barrier.

Context - After the recession of 2008, the real estate market is picking up again. Amongst others due to the urbanisation and the increasing world population the real estate demand is growing. However, the current scarcity of workforce in the construction industry might become a huge issue in the future. In order to deal with the future real estate demand, the conventional construction industry needs to change. Although other industries are gratefully using newly developed technologies such as robots, innovations on the construction site are hardly used. Objective - This thesis aims to investigate how a business model of a Dutch construction company has to change to make on-site robots feasible. This research provides different strategies for construction companies to implement robots for the construction of row-houses, in order to deal with the emerging issues. Methods - This research is divided into three parts. The first section is a literature review providing an overview of currently developed robots, the status of the construction industry and the business models of construction companies. Secondly, an empirical part in which interviews are conducted to find out what the current business model of Dutch construction companies looks like. In addition, a case study in the dairy industry has been conducted as inspiration. In the final part, the operational section, all gained knowledge is combined and formulated as input values for the design of the adjusted business model. This is validated and complemented through a focus group with experts from the construction industry. For this research, the Business Model Canvas of Osterwalder and Pigneur is used as a framework. Results - Three different strategies are designed, based on the current business models of construction companies. These proposed models are adjusted to the input of the chosen robot, the case study in the dairy industry and the outcomes of the focus group. In the business model of the first strategy, the construction job is outsourced to a sub-contractor, who responsible for the operation of the robot. Within this model, minimal adjustments are needed for the construction company itself. However, this is the most expensive way to construct. In the second strategy, the robot is also implemented as key partner in the current business model, in this case not as sub-contractor but as a supplier. The robot is rented by the construction company from an external equipment party. This scenario will require adjustments of the current business model. Although this business model is less costly than the first model, it is still more expansive than currently used construction methods. The last strategy implies the purchase of a robot by the construction company itself. The impact/influence on the business model is shown for a worst and a best-case scenario. This strategy will cause several changes within the current business model, of which the most important is the robot as new key resource. The difference in costs depends on the worst or best scenario. The worst scenario, turned out to be the most expensive one, while the best scenario will just have minimal impact on the costs. Conclusions - Three different strategies are designed with matching business models for the implementation of on-site robots by construction companies. Therefore, it is impossible to develop one generic business models. Hence, the adjusted business models matching to the three possible strategies are based on a merged business model of all the participating construction companies. For each of the strategy, specific adjustments need to be made in the current business model. The first business model, in which the robot will be implemented by a sub-contractor turned out to be the most expensive scenario. Nevertheless, according to the practice, this will be the most promising scenario to start implementing robots. The fact that construction companies take a passive position towards innovations confirms the findings from the literature study that concludes that construction companies are described as traditional and conservative. However, when the urgency for the use construction robots grow, due to an increasing shortage of workforce, it is more likely that the last strategy will be implemented; the purchase of a robot by the construction company itself. This will be the most obvious one, regarding costs, efficiency

The construction industry has always been an important driver of the economy. An important part of the projects in this industry is commissioned by public entities. However, recently a trend can be observed in which the procurement process fails more often than before. Due to the current times of economic expansion in the Netherlands contractors are more selective in project selection. Failed procurement processes are however undesirable since the transaction costs and time invested in such a process can mount up. Many scholars have investigated the bid decision of contractors (Bagies & Fortune, 2006; Shokri-Ghasabeh & Chileshe, 2016). Yet, in order to contribute to solving the issue mentioned above not all considerations of contractors are relevant. Therefore, this research specifically focused on those considerations, or decision attributes, that a client can influence during the tender design phase. Resulting in the following research question: “What tender design related attributes are key decision drivers in the contractor’s bid decision and how do these key decision drivers influence the bid decision in economic times of expansion for publicly procured non-residential construction projects in the Netherlands?”