The increasing emphasis on sustainability in the built environment has led to the adoption of voluntary green building certifications such as BREEAM-NL. While the financial benefits of environmental certifications are well-documented in commercial real estate markets, research on their impact in residential markets remains limited, particularly in the Netherlands. This thesis investigates the effect of BREEAM-NL certification on residential transaction prices in the Dutch housing market using a hedonic price model.
A comprehensive dataset of residential property transactions is analysed, controlling for property characteristics (e.g., area, number of rooms, and year of construction), locational attributes, and neighbourhood factors (e.g., crime rates and proximity to amenities). The analysis reveals that BREEAM-NL-certified properties command a statistically significant price premium ranging between 7.2% and 15.7%. These findings align with international studies on the added value of green certifications but indicate a slightly larger premium in the Dutch residential sector.
The results highlight the economic feasibility of green certifications, offering valuable insights for developers, investors, and policymakers. For developers, the premium demonstrates that sustainability investments can yield tangible financial benefits. Policymakers can use this evidence to design targeted strategies and incentives to encourage broader adoption of green building standards.
This research fills a critical gap in the literature by providing empirical evidence on the impact of BREEAM-NL certification in the residential housing market. The findings support the role of green building certifications in driving economic value while contributing to broader sustainability goals.0

The construction sector is essential for societal functioning yet faces significant challenges, including shortages in physical and human resources, extensive material and energy use, and low productivity growth. The Dutch construction industry, in particular, is grappling with a housing deficit, rising construction costs, and restrictive nitrogen policies. Additionally, a complex situation with infrastructure rehabilitation, known as the V&R challenge, demands immediate attention. This research focuses on the rehabilitation of bridge infrastructure assets, many of which were built in the 1950s and 1960s and now require renovation or replacement. The surge in demand for these activities is expected to surpass the current supply capacity, necessitating a transition in infrastructure project execution towards industrialisation.

The study analysed the concept of industrialisation in the Dutch bridge infrastructure context, aiming to understand how innovations and sector characteristics influence the potential for an integrated industrialised value chain. Using a qualitative methodology, the research employed the Technological Innovation Systems (TIS) approach, supported by semi-structured interviews. The findings indicated that while numerous innovations could contribute to industrialisation, no singular combination ensures an industrialised value chain due to contextual factors. A proposed framework, the Industrialised Infrastructure Construction (IIC), outlined conditions necessary for a functioning industrialised system, including continuity of demand, standardisation, and long-term relations, amongst others.

The TIS analysis identified several systemic barriers: lack of upfront coordination and long-term planning, insufficient support for innovation and knowledge exchange, a conservative culture in a competitive sector, and insufficient interdisciplinary collaboration. Addressing these barriers through policy instruments and organisational strategies is crucial for fostering transition efforts. Further research is recommended to validate the IIC framework and explore the cultural impacts on sustainable innovation. Practical recommendations emphasise the importance of interdisciplinary collaboration and long-term commitment to standardisation for all actors involved in bridge rehabilitation.

Sustainable development faces substantial challenges, with the built environment emerging as a major contributor to resource consumption. Office retrofitting, commonly known as changing the office fit out, is a common process in corporate real estate and accentuates these challenges due to its linear model of extraction, production, consumption, and disposal of building materials. This model leads to considerable waste and greenhouse gas emissions. This research examines the inefficiencies of the current linear model and explores transitioning to a circular office fit-out, which aims to minimise resource use and waste. The study focuses on the tenant-landlord relationship in corporate real estate, as these stakeholders are crucial for enabling circular fit-outs. The research question addressed is: “How can the tenant-landlord relationship facilitate the process from a traditional to a circular fit-out in office buildings?” Mixed methods, including literature review, case study documentation, and interviews, were used. What was found was that the relationship can enable circular practices if the stakeholders show positive behaviour, expertise, commitment, share information and communicate well, have a promoting business strategy around the fit-out product, and are pushed by society. Furthermore, the lease agreement showed to be crucial, and could enable circular practices even more than the actual fit-out design. Although these mentioned relationship determinants and arrangements are important, the research showed it is important to recognise the stakeholders individual responsibility towards circular practices. The research concludes with recommendations towards each stakeholder.

The Dutch construction industry mainly operates on a linear economy model. However,
transitioning to a circular economy (CE) is seen as essential for meeting climate change
objectives and adhering to the Paris Agreement. However, the industry has been slow to
adopt CE principles, primarily due to its inherent aversion to risk and resistance to
change. This reluctance is further compounded by cognitive biases among stakeholders,
which create a "lock-in" effect that favours traditional practices over CE innovations.
The main question this research seeks to answer is, "How does cognitive lock-in at the
regime level of the construction industry hinder the implementation of the circular
economy?"
This research aims to explore how cognitive lock-in at the regime level impedes CE
implementation by examining socio-cultural barriers and the impact of cognitive biases
on decision-making processes.

Cities have become global hubs of economic prosperity, drawing on well-established infrastructure, abundant human resources, and dense industrial networks. However, this rapid urban expansion has strained existing infrastructure and services, compounded by challenges such as climate change, resource depletion, and social inequality. Historically, urban development patterns, characterized by linear production and consumption models, have led to significant waste generation and resource degradation, with adverse effects on the environment and human habitats. Under these circumstance, the idea of a circular economy (CE) has gained widespread recognition. Governments, including those of the Netherlands and China, are actively promoting CE principles and integrating them into urban planning...@en

This research investigates the integration of environmental costs into the cost-benefit analysis (CBA) framework for constructing circular viaducts. Circular viaducts offer environmental benefits but face challenges due to their higher initial construction costs. The traditional CBA framework focuses solely on economic costs, hindering the adoption of circular construction. This research proposes a methodology to monetize environmental costs and integrate them into the CBA framework to make informed decisions about circular viaduct construction.
The methodology involves analysing the environmental impact of circular viaducts and traditional viaducts using Life Cycle Assessment (LCA) and Environmental Product Declarations (EPDs). The environmental impact is then monetized using agreed-upon values from various stakeholders. The monetized environmental costs are incorporated into the CBA framework using cash flows and the net present value (NPV) method.
The research findings indicate that the implementation of circular viaducts is most viable in scenarios with longer lifespans. In these scenarios, the overall environmental costs of the circular viaduct are lower than those of the traditional viaduct due to the lower frequency of replacement. However, the NPV analysis reveals that the traditional viaduct has lower present value environmental costs in all three scenarios. This is due to the difficulty of accurately predicting future material prices, which could significantly impact the economic benefits of material reuse in the circular viaduct.
Results show that while the circular viaduct exhibits higher environmental costs in some scenarios, its economic benefits through material reuse, particularly in scenarios two and three, make it a more viable option. However, further research and development are needed to reduce the initial environmental and economic costs of circular viaducts to achieve a wider and faster adoption of this sustainable construction method.

The pursuit of global sustainability goals has triggered a shift in national strategies, with countries like the Netherlands adopting innovative policies to realize circular economies by 2050. Circular area development, a novel approach, is emerging as a key strategy in this transition. It focuses on optimizing resources within specific geographic zones, considering their entire lifecycle, to minimize waste and establish sustainable loops. This study addresses the underexplored dimension of inclusiveness in Dutch circular area development, aiming to formulate guiding principles through literature review and semi-structured interviews. These principles offer a roadmap for policymakers, stakeholders, and practitioners to promote circular strategies while ensuring inclusivity. The research question guiding this study is: How can inclusiveness principles facilitate and advance the implementation of circular strategies in Dutch Circular Area Development? By exploring themes like stakeholder engagement, education, access, sustainable practices, and local adaptation, the research offers a comprehensive framework for integrating inclusivity into circular strategies. The study emphasizes the importance of trust, communication, and equitable participation, highlighting their role in fostering successful circular area development. Ultimately, the identified principles pave the way for a more inclusive and sustainable circular economy.

Amid global climate change challenges, the construction industry faces an urgent  transition from a linear production model to a Circular Economy (CE). Initiatives  and recommendations in Dutch transition roadmaps and literature predominantly  focus on ensuring a future circular built environment, while lacking concrete actions on leveraging the existing assets for reuse. Dutch CE roadmap timelines  and interventions are developed based on Material Flow Analysis (MFA) studies with highly uncertain data input, this uncertainty impacts either environment or  economy with inaccurate interventions on the CE-transition. Secondly, the Replacement & Renovation (R&R) task of civil structures poses a threat for the  industry due to the limitations of capital, contractor capacity, and material  resources required to facilitate this peak. There is currently a lack of centrally  stored high-quality physical asset data available at public organisations. This data is essential in effectively managing the decommissioning peak and reduces risk for reuse realization. Lastly, Asset Management (AM) is transitioning towards a 3D-centralised strategy in line with Building Information Modelling (BIM) and  digital twins, while existing assets are still in 2D with often incomplete and  fragmented data documentation. Consequently, a large data quality gap is forming between new and existing assets. This led to the research question: How can centrally stored, quantified, and visualised asset data of existing infrastructure impact the CE-transition, bridge R&R-task efficiency, and AM practices? An upgrade towards 3D-BIM is required for existing assets to bridge this data gap. In doing so, facilitate higher quality- and more accessible asset specific  information that can be used in reusability scanning and structural assessments,  material quantification for CE-transition roadmap accuracy, and numerous AM  benefits. The costs for upgrading the existing assets using manual modelling or  3D scanning technology are currently too large to justify. An opportunity was  identified for modelling 3D-BIM of existing beam & slab bridges from 2D drawings using a modular approach to Parametric Engineering, aiming to reduce the investment threshold, and accelerating the digitization transition. Preliminary testing executed by the author showed a potential for 50-80% reduction in modelling efforts compared to conventional modelling practices with a volume  accuracy of >97%. The prototype calls for further development, validation, and similar efforts for other infrastructure types. The tool also showed potential for 3D structural & reusability assessments, reinforcement approx., and ptioneering & circularity scoring for the design phase. To put the tool’s use in perspective, a roadmap towards 3D centralized AM and a reuse economy was developed for AM.

The Netherlands aims to have a fully circular economy by 2050. The construction sector in the Netherlands is only 8% circular (Circularity Gap Report Bouw, 2022). Reuse within construction projects presents various challenges, which will be discussed in this thesis. In the current market, there is more supply than demand (BAMB, 2020). One possibility to stimulate demand is the use of digital marketplaces. This study investigates how a digital marketplace can support the demand side in the design process, leading to the following research question:

How should a secondary ‘digital’ product marketplace function within the construction industry?

Before addressing this question, a literature review is conducted on various aspects. These include the concepts within digital marketplaces and platforms, as well as those within reuse projects, focusing on specific information about materials and products in the context of reuse. Additionally, the current state of the industry has been examined in terms of challenges, opportunities in general, and those related to digitalization. This is done to get a better understanding of the surroundings in which the marketplace must operate.

The literature research concludes that the core interaction is the most important form of activity on a platform – the value that attracts the most users to the platform in the first place (Parker et al., 2016). It consists of three parts: Participants + Value Unit + Filter. Fundamentally there are two participants on the platform, namely producers and consumers. In this case, producers are building/construction elements and their owners/sellers. Consumers are the ones that are willing to buy them (potentially; architects, engineers, contractors, or suppliers). Where the value unit starts with the exchange of information that has value to the participants. This information delivery to consumers depends on filters. A filter enables the transfer of appropriate value units between users. A well-designed filter ensures that platform users see only information units that are relevant and valuable to them. No filters or a poorly designed filter overwhelms users with units they find valueless and irrelevant, which causes them to abandon the platform. No research has been done to the specific design of the core interaction of a secondary product marketplace within the construction industry.

In addition, few scientific articles investigate software interfaces, ease of use and the user's role and experience within the construction industry. An action- and design-oriented research method is a new approach to this problem/goal. The information system framework is chosen to combine rigor research and the application domain within a design practices.

To structure this research the research question is divided into three steps (based on the core interaction). In step 1, the input for the design is investigated, which includes determining the participants who should use the marketplace (champions), how they should search for products, and what improvements can be made in the design process to promote reuse. In step 2, the filters and interfaces of the marketplace are designed. Within step 2, solutions for situations with limited data or, conversely, when there is sufficient data in the future are also explored. In step 3, the chosen champion validates if they can use the designed solution and whether it provides value.

To define the main users/champions (step 1), potential users-(roles) are interviewed about their needs for such a marketplace, assuming reuse becomes the norm. The literature review covers all aspects of digital (construction) applications and reuse in the construction industry. This is supplemented with expert interviews in IFC (an open data standard), user interface/user experience (UI/UX), current construction marketplaces, and material passports. In addition, various roles from several reuse projects are interviewed, including designers, project developers, purchasers, demolition specialists, and engineers, in line with the information system framework and action design. This is done to get an complete overview of all the stakeholders involved within the process of selecting/buying reused products.

The information of the literature research and the first interview phase is used in the design process to create ‘search and facet’ filters. Therefor a division based on the Brand/shearing layers (site, structure, services, skin/facade, space, and stuff) is made to improve the design the facet filters. The engineer and the architect is chosen as the primary user but in consultation with the design team. For all the engineers responsible or related to the a Brand layer a recommendation is made for a first set a (search) parameters.

Concerning the information need (step 2) of the structural engineer, the primary focus is on the elements' functional and physical properties (moment-of-inertia, material type, strength, and dimensions). Thereby the core interaction disregards environmental or economic properties. These are of secondary interest for the core interaction. The three main materials, wood, steel and concrete, require all different ways of working for reuse but share common properties which makes the design of filters less complex. Capacity, dimension, grid size, floor height and more properties could influence the structural design decision, increasing the demand for reusable structural products. However, more traditional engineers prefer to filter within one type of material. Even more in-depth material and product knowledge for reuse could is a next step for the core interaction, thereby evolving into a knowledge marketplace.

The other Brand layers (skin, services and space) information need should also focus on their functional and physical reusability properties, which are covered and designed in this thesis but not validated with real users. The skin and the space layer are more visually oriented; images support the architect's and engineer's decision-making. Aesthetic filters to filter on certain styles, colours, types and tags will support the architect where functional filters relating to dimension are of first need for the façade engineer. Secondly the physical filters benefit the search tremendously, such as; U-value, fire resistance, Rc-value, sound resistance, waterproofness etc. The service/building engineer wants to filter into three categories. Namely the machine, the distribution point (ventilation grille, water tap, heating element) and the transport (cable tray, pipe and wires). The machine (e.g., heating, cooling and air filters) has a more dynamical environment with a high change in regulation, expecting a low reuse pattern. The other two categories, distribution and transport are more suitable for reuse; these filters contain service type (energy, water, air, data and heating), minimum length and the capacity of distribution and transportation.

After step 2 (design) various structural engineers are interviewed using a working digital prototype to examine whether the search filters are effective for their reuse process (step 3). Besides various side notes on the design culture, system changes and the willingness of a client to reuse products. The interviewed users made recommendations which should be taken into account for a next design iteration. The proposed design is usable and could meet its goal/value proposition when reusing products becomes the norm.

This research is a small link in the bigger picture of a ‘circular’ construction industry. Still, many challenges remain that a digital marketplace could not solve. When interpreting the results, the following points should be considered as well. The interviewees in this research are involved or interested in reusing products. When less interested engineers/users must use this marketplace, other items could be of more importance or totally different obstacles could arise.

Further research should examine the other Brand layers and their primary users. Additionally, to succeed as a marketplace, choices need to be made. Which users and product categories will be supported in first place. What is the business plan and initial investment? Building and rolling out a marketplace requires entrepreneurial skills and courage. This research hopes to provide the readers with a holistic view of all the challenges related to a digital market platform that address the construction market for secondary materials. Together with a set of validated user interfaces of such marketplace.

People are the main asset of a consultancy firm, and a Project Manager is a key figure in the delivery of projects. Change Management theories suggest that the success of change efforts relies on three components: Leadership, Project Management and Change Management. Therefore, successful sustainability implementation depends significantly on the performance of a Project Manager, how well they are equipped with the knowledge about sustainability and supported with tools and internal processes. But first of all, how well they are aware of the importance of sustainability for the organisation and how strong their intention to implement the changes is.
The project manager, as an enabler of sustainability in a construction project, can contribute to the construction industry to meet sustainable development goals. To facilitate the process of sustainability implementation and create opportunities for action, more knowledge is required about current drivers and barriers for the project managers. This research investigated these drivers and barriers utilising behavioural theories.
Main results
The research design used a mix of qualitative and quantitative methodologies. The literature and organisational documents were used to study the current state of sustainability implementation in theory and practice, and at the same time, several exploratory interviews were conducted. DINAMO survey identified which barriers PM specialists encounter during project delivery. Four main barriers resulted from the survey:
• Complexity of the change
• Lack of Information
• Lack of Involvement
• Manageability of the change
Main conclusions
The study has indicated three points that can help to translate sustainability into project execution.
First, the research has shown the importance of the strategic context. Explanation of the strategic goals and their alignment with other organisational goals plays an essential role in strategy implementation.
Second, it has been concluded from the study that project management practices require significant revisions. Being a key figure in the project, PM must enable opportunities for sustainable goals. Sustainable goals should be inseparable from the project’s success, and the integration of these goals must be facilitated by sustainability leadership.
Third, the study has disclosed that the behavioural control and intention of project managers to change play a significant role in the implementation of sustainability in projects. Behaviour is directly dependent on the working environment created by strategic settings. It is, therefore, a closed loop in which strategic settings influence the behaviour, and behaviour can provide valuable information to re-adjust the strategic settings.

The world is facing environmental change, mainly due to human actions. To prevent serious environmental, economic, and societal impacts of climate change, all United Nations Framework Convention on Climate Change (UNFCCC) member countries have committed to limit global temperature increase to 2 degrees Celsius above pre-industrial level by 2050. Current mitigation measures, like moving to renewable energy, are not sufficient. Implementing circular economy can address this issue. A transition is required to move from a linear to a circular economy. The main research question for this research is: What can be learned about targeting the transition to a 100% circular Dutch infrastructure sector in 2050, through three social agreements if we take the perspective of Mission-oriented Innovation System (MIS)? This research also provided input for the second Integral Circular Economy Report (ICER) of 2023.
The Dutch economic model operates in a predominantly linear economy. The three principles for circular economy are: eliminate waste and pollution, circulate products and materials and regenerate nature. A large renovation awaits us. The very long lifespan of infrastructural projects makes the transition in this sector challenging. One of the four central frameworks to study transitions is the Mission-oriented Innovation System (MIS) approach. To tackle grand societal challenges, MIS also takes non-technological innovations into account. To see whether something has been learned from the transition process, four learning dimensions in sustainability-oriented learning have been identified. By pursuing all four dimensions, properties can be developed to take steps toward building a circular world.
The three cases studied for this research concern the materials concrete, wood, and steel. Per case a separate MIS analysis has been performed. The three cases have been generalized into two different categories: the “already established materials” and the “yet to be introduced materials”. The main dynamic in the already established materials is the negative feedback loop between the market formation and destabilization, availability of human and financial resources and the lack of directionality. Moreover, the lack of coordination also negatively affects the entire system. For the yet to be introduced materials the non-supportive socio-technical environment is the root cause of many negatively influenced system functions. Due to the lack of a supportive environment, there is a lack of financial resources which causes insufficient knowledge development. The lack of knowledge has as a result no clear direction for the transition and little possibilities to create a market for the new material.
The research question consists of four main elements: learning, transition, circular economy, and the MIS perspective. From studying the transition to a 100% circular Dutch infrastructure it can be learned that taking the scope of a social agreement can be a good start. In line with the learning dimension about boundary crossing and system thinking, the next step it to broaden the view. Also, there should be special attention to the successes in the strategy “narrow the loop” to motivate people.

This research addresses the critical issue of the poor implementation of sanitation and its effect on community and environmental health in the Global South. To overcome the social, cultural, technical, and financial complexities underlying poor sanitation, the participation of local community members in sanitation planning processes is deemed crucial for the successful development and implementation of sanitation systems.
To engage local stakeholders as decision-makers and improve design freedom, it is proposed to engage stakeholders in determining their demands, needs, and priorities by combining the Fuzzy Analytical Hierarchy Process (FAHP) and Focus Group Discussions (FGD) as a participatory decision-making method. The applicability and suitability of this method are assessed through a case study in Hagonoy, the Philippines, in which two parallel design cycles are carried out: one with only local sanitation experts as decision-makers and one with only local community members as decision-makers. A systematic literature review of design criteria applicable to sanitation design processes was conducted to overcome selectors' bias regarding the decision criteria assessed in the FAHP and the FGD. The FAHP data was collected among 60 community members evenly distributed over six neighbourhoods in Hagonoy and six local sanitation experts. Three FGDs were held with local community members, whilst one FGD was held with local sanitation experts. The design cycle based on the defined design scope was limited to the development of a conceptual design, proposing a treatment train capable of treating the produced domestic wastewater such that the effluent satisfies the local General Effluent Standards, specifically for the parameters water volume, Total Phosphorus (TP), Chemical Oxygen Demand (COD), Ammonia (NH3), and Nitrate (NO32-). Wastewater treatment technologies aligning with the demands and needs specified by the stakeholders were obtained from scientific literature, which were combined into a sanitation system configuration that could treat the water sufficiently.
The completion of a sanitation design process without predefining the possible solutions, but by integrating the FAHP + FGD in the systematic derivation of the design scope, demonstrated how a demand- and need-driven design approach allows increased flexibility and sensitivity for the context in the development of a design. The parallel design cycles showed how the FAHP + FGD method could be applied as a systematic procedure to understand how design criteria in sanitation design are preferred and interpreted differently between local community members and local sanitation experts and how this can influence the conceptual design. Altogether, this research contributes to the body of knowledge in community-engaged sanitation design by demonstrating the effectiveness of the FAHP and FGD method in engaging community members in a need-driven design process, overcoming selectors’ bias for technologies and trade-offs, and producing relevant design proposals. However, acknowledging that the FAHP + FGD method was limited to engaging stakeholders only in defining the needs and demands, verification of the designs’ alignment with the perspectives of stakeholders and continuous engagement throughout the entire design process is essential to be further researched in the future.

Green roofs can play an important role in reducing problems in urban areas by being flexible, multifunctional and adaptable. These features of nature have proven effective in combating climate change and contribute to human well-being. Previous research has shown that green roofs can sometimes be cost-effective, but the benefits included in cost-benefit analyses are fragmented and an absence of a learning curve in the literature regarding green roofs is discernible. This research focuses on how to determine the economic value of the benefits of green roofs and what methodologies are used to do so. There is also a need to bridge the gap between research on costs and benefits and research on external costs of production materials. This research contributes to bridging this gap by creating a full life-cycle cost-benefit analysis of a green roof by mapping and analysing current methodologies. This research contributes to sustainable development and in it serves as a starting point to determine the utilisation of green roofs with the pursuit of sustainable urban development.

It is observed that both cost and environmental impact are underemphasized criteria in the investment decision-making process of Institutional Real Estate Investment Funds (IREIFs). The limited adoption of Life Cycle Costing (LCC) and Life Cycle Analysis (LCA) within IREIFs' Performance Management Systems (PMS) hampers improved investment substantiation. This study aims to develop an LCC tool that accounts for environmental impact and to explore its potential implementation within an IREIF's PMS. The research question addressed is: 'How can an IREIF incorporate sustainability, defined here as both environmental and economic factors, into its decision-making process through LCC?' A double diamond design research approach led to the development of an Environmental Impact (EI)-LCC tool that monetizes environmental impact. This tool serves as a performance measurement instrument, offering insights into the environmental and cost implications of building elements over their lifespan. The study also discusses the tool's integration into an IREIFs existing Internal PMS as their Environmental, Social, and Governance (ESG) performance framework. Preliminary findings indicate that the EI-LCC tool, although in a nascent stage, has the potential to enhance the quality of sustainable investment decisions within IREIFs. The results provide a foundation for the tool's further development and broader implementation within the PMS of IREIFs.

The increasing generation of municipal solid waste (MSW) due to urbanization and population growth has highlighted the importance of effective Municipal solid waste management. Waste sorting plays a critical role in enhancing waste quality and boosting recycling rates, aligning with the circular economy goals of the European Union. However, despite significant waste production in cities, limited separation and recycling occur, primarily due to insufficient citizen involvement. When it comes to involving citizens in sorting household waste, there has been limited research and exploration of the waste sorting behavior of college students. Given that the majority of college students reside in student housing, the research aims to understand college students’ waste sorting behavior in student housing and recommend interventions that motivate students to engage in waste sorting.

To attain the objective, the research utilized a mixed research approach, initially employing semi-structured interviews as the qualitative method and subsequently conducting an online survey as the quantitative method. Qualitative results were derived through the application of thematic analysis and subsequently served as a basis for constructing the questionnaire survey in the subsequent quantitative phase. The factors that impact waste sorting behavior in student housing were identified and quantified in the quantitative phase by employing the partial least square structural equation modeling (PLS-SEM) method.

The results revealed that the subjective norm and perceived behavioral control directly impact students’ intentions to engage in waste sorting, which in turn, indirectly affects their waste sorting behavior. In addition, the waste sorting facilities and information publicity holds a significant influence on the students’ household waste sorting behavior.

Based on the findings, it is suggested that the intervention aimed at encouraging waste sorting among students could involve enhancing the publicity of waste sorting information by providing information prompts in the communal space within student housing and distributing information through social media. Furthermore, interventions like improving the waste sorting facilities could engage students in waste sorting. Additionally, promoting communication within the student housing community and incorporating waste sorting education into the college curriculum were also suggested as interventions to incentivize students to sort their household waste.

On a general level, the Dutch government wants to have a fully circular economy by 2050 by reducing the use of primary materials and carbon dioxide emissions. As the consideration and integration of concepts such as sustainability and circular economy are becoming increasingly popular in the civil engineering sector, it might be time to re-consider certain activities.

From both scientific and practical points of view, it is concluded that currently a great deal of research is focused on stimulating concepts such as sustainability and circular economy in the “early stages” of the lifecycle such as procurement, design, and construction stages. However, the aforementioned concepts are not yet elaborately researched in stages after construction, such as the maintenance stage. However, in the Dutch context, there are hundreds of existing civil engineering assets, that need to be maintained daily. As the Dutch government has certain goals, it is important to see how maintenance strategies for existing civil engineering assets can be affected in the case when sustainability and circular economy are considered.

This research aims to explore the integration of concepts such as sustainability and circular economy within the maintenance stage of existing civil engineering assets. As a result of this research, a tool is developed in Microsoft Excel. This tool referred to as “Maintaining sustainably and circularly in a collaborative way” can be used by actors involved in the maintenance stage. It is possible to apply the tool in the following two phases, namely (1) the pre-contractual phase and (2) the execution phase for maintenance works. With the help of indicators, the actors involved can (re)consider aspects such as the (current) maintenance strategies, and the requirements for maintenance contracts. The tool can help to overcome certain identified barriers such as knowledge gaps on sustainability and circular economy within the maintenance stage, and diffused collaboration among parties involved in a certain process.
For this research, two important constraints to mention are:
(a) The developed tool is currently only applicable for sluices and bascule bridges (in Dutch: beweegbare bruggen), and
(b) the focus of this research is solely on performance-based contracts for maintenance works.

As an approach to conducting the research, the “Double Diamond Methodology” is applied. This is a design-thinking research approach. In the first part of the diamond, literature is reviewed and semi-structured interviews are conducted. The results of the literature review and the interviews led to the requirements that should be used as a basis for developing the tool. In the second part of the diamond, the tool was developed and tested via validation sessions.

Urbanization is putting more pressure on waste management infrastructures in cities, which could lead to “inadequate and overburdened infrastructure” according to the United Nations (United Nations Statistics Division, 2019). Because people play an important role in the performance of waste management systems, the systems should be inclusive to all people (Vasconcelos et al., 2021). As currently no method suffices in studying both inclusivity and circularity in waste management processes this study proposes the waste journey method.

The waste journey method combines the customer journey theory and the theory of planned behavior and can be graphically presented as in Figure 1. In the waste journey method, the waste is followed from a waste perspective from actor to actor. In this journey the waste interacts with people, called touch points, who take certain actions that influence the circular performance of the waste management process. By mapping the waste management process and analyzing the arguments actors have for their actions, with the theory of planned behavior, the barriers, and opportunities for realizing inclusivity and circularity in a waste management process can be identified.

The barriers and gaps that are identified with the waste journey method can contribute to the improvement of the waste management process. Besides, this method is one of the first to recognize the preparation phase as an important phase for the circular performance of the waste management process. A downside of the waste journey method is that it is a time-consuming method to use, and it requires the transparency and willingness of all actors in the waste management process. This was also experienced in the case study where one of the actors was not willing to cooperate and commercial actors were not transparent about their waste trading contracts. Furthermore, the interview protocol of this research could have been better specified for each actor. Future studies should focus on implementing this method on other waste streams and developing the definition of inclusivity and specifying it for each actor in the waste management process

The concrete armour unit industry exist for more than 70 years, in this period various units were developed. The first units derived their hydraulic stability on their own weight, later the units got more complex shapes and got interlocking capabilities. The first interlocking units were placed in a two-layer configuration, like Tetrapod and Dolos. Later the industry shifted to a one-layer design where concrete use became less since fewer units were needed. The industry standard of one-layer gave rise to various new armour units, like Core-Loc and Xbloc.

Up to the present, this industry is mainly studied from a technological perspective where the hydraulic capabilities and design formulae are extensively researched (so called 'hard factors'). However, some units became very commercially successful in terms of units placed but others did not. In this highly technological industry, no market research is done in order to study which factors led to commercial success.

In this study, an effort is made to investigate which factors are responsible for becoming successful in this branch. To do so, the concept of technological dominance is linked to this industry. Technological dominance is a technology management concept wherein a market similar technologies are ‘battling’ for the allegiance of the market. Eventually, the market selects a particular design and becomes dominant.

Over the years scholars identified factors that contribute to obtaining technological dominance and collected those in a framework. In this study, the framework by Van de Kaa et al. (2011) is chosen. This framework consists of 29 factors that influence the outcome of a technology battle.

The methodological approach for this study is to select relevant factors regarding this industry by interviewing 4 key experts. The identified relevant factors are then carried into the next round of interviews, where a broader group of 14 experts were asked to rank these factors according to the Best Worst Method.

The Best Worst Method (BWM) is a multi-criteria decision-making tool, designed by Rezaei (2015), where the decision-maker expresses their preference by making pairwise comparisons. This method gives more reliable weights and requires fewer pairwise comparisons in respect to other multi-criteria decision-making tools, like AHP.

The results yielded by this method suggest that the factor ‘brand reputation and credibility' are among experts considered as the most important factor for technological dominance regarding this industry. Furthermore, ‘hydraulic stability’ is in this branch considered second most important for obtaining technological dominance. Also, factors like 'marketing communications' and having a large network of stakeholders are considered very important. Based on the results, there can be concluded that in this technological branch soft factors can be more important than hard factors.

This implies that in order to be successful in this industry actors should focus more on building a reliable and well-known brand reputation. In this branch, actors have proved that a strong brand name can help to extend the commercial lifespan of an armour unit with expired patent and can help to speed up the adoption of new armour units.

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 construction industry (CI) has to transition towards a circular economy (CE) before 2050 to achieve the ambition of our Dutch government. Within the CI there is an information gap leading to suboptimal recycling and reuse of materials and products. Capturing and sharing this information in a digital tool will be critical for the construction industry to make the transition to a CE. A material passport (MP) is seen as a collaboration tool that could close the information gap and promote the CE transition within the CI. There is little empirical data on MP implementation within science and practice, and the development of different MP initiatives is not harmonised. To standardise the development of MP’s so that data will be interchangeable and comparable, platform CB’23 has created guidelines for MP implementation and development. The objective of this research is to capture the lessons learned, and identify barriers and objectives for implementation within practice. With the goal of sharing these practical insights in order to assess the work agreements of the guidelines for practical applicability, achievability, and future development. This research has analysed a first-of-its-kind BIM-based MP implementation for a new building in the Netherlands.

Reflecting the findings of this research against the broadly accepted work agreements of the guideline, it can be concluded that implementation within practice is much more unruly and ad hoc than the suggested implementation guideline and road towards standardisation. Within this research, multiple discrepancies have been found that could create a barrier for effective implementation with respect to ease of use and could impact the added value of the tool over the lifetime of the construction. Private and public support of the work agreements is not aligned and could lead to the separation of MP development. Nevertheless, parties recognise the need for data registration in order to transition towards a circular economy. MP development should work towards creating the essential committed cooperation of all parties in the value chain, as within a circular economy the whole value chain should be involved. This could either mature through governmental involvement or market force, but balancing the economic and societal values of stakeholders within the value chain will become necessary to ensure the full potential of the tool to facilitate circular material flow within the construction industry. Future research should gather more empirical knowledge, and it is recommended that perspectives from both private and public clients be included.