This study explores how storm surge barriers, essential for protecting flood-prone urban regions like the Texas Gulf Coast, can be designed to remain reliable and adaptable over their 100 year lifespans despite unpredictable environmental and socio-economic changes. Traditional flood defenses like dikes are often unfeasible in dense cities, prompting the adoption of movable storm surge barriers. However, fewer than fifty such barriers exist worldwide, and operational knowledge remains fragmented. Once built, barriers must maintain near-perfect reliability despite unpredictable factors such as sea level rise, changing vessel sizes, and institutional shifts, conditions that standard design practices often fail to accommodate.

Focusing on the proposed Bolivar Roads Gate System, the research integrates operational and maintenance needs into early design and planning. It applies the Flexibility in Engineering Design method to identify and evaluate how external drivers, like relative sea level rise and economic development (particularly increased vessel drafts), affect long-term barrier performance. The study maps dependencies between critical system drivers and barrier components, identifying the sill as the most risk-sensitive and costly to modify. As a result, it proposes an innovative, adaptable sill design: a two-stage structure that can be upgraded in the future to accommodate deeper vessel drafts, allowing the barrier to “change” rather than fail under unanticipated pressures.

The study also identifies the importance of designing for maintainability. Barrier components have varying lifespans, electrical (8–15 years), movable (50–100 years), and fixed (100 years), which demand different maintenance intervals. To address this, the research advocates for a maintainability-first design strategy, such as placing short-lived components in easily accessible locations. Maintenance should follow a state-based policy, combining preventive, corrective, and failure-based actions depending on the component’s role and risk level.

From a governance perspective, the study highlights the need for public clients to act as system integrators, balancing in-house oversight with selective outsourcing. The delivery of such complex infrastructure requires differentiated strategies across phases: detailed design should remain tightly managed in-house, while construction and certain maintenance tasks may be outsourced. Operational control, due to high reliability demands, should stay within the public domain. The governance of adaptable components, like the sill, must also remain with public authorities to ensure activation aligns with policy shifts.

Ultimately, the research proposes a bimodal strategy for barrier management. Mode 1 focuses on maintainability and predictable reliability through conventional design and maintenance practices. Mode 2 embraces uncertainty, embedding flexibility into components to adapt over time. This approach enables barriers to function as dynamic, living systems, built to endure, but also to evolve. By embedding adaptability in the most permanent elements and pairing it with tailored maintenance strategies, public agencies can maintain flood protection, performance, and accountability in the face of long-term uncertainty.

In recent years, there has been a growing interest in the potential of digitalisation to enhance dispute resolution practices in construction projects. Research highlights that the social aspect is an important element in both the successful implementation of dispute resolution methods and the adoption of digital technologies in the construction industry. Culture has the ability to influence this social dimension, shaping behaviours and practices. However, insufficient research has examined the extent to which culture influences the successful implementation of digital technologies in dispute resolution. While most of the existing literature focuses on dispute resolution and digital tools in the context of mega projects, small-scale projects constitute a vital part of the construction industry. Currently, there is a gap in knowledge on how culture influences the successful implementation of digitalisation of dispute resolution in small-scale projects.

The research question that links to this problem is formulated as follows: 'How can culture shape digital dispute resolution practices?'

This thesis discusses an extensive literature review on the concepts of culture and digital dispute resolution, and presents the results of a case study comparing perceptions about digitalised dispute resolution practices in an English and Dutch office fit-out project. Stakeholders within the projects were interviewed for this study, followed by a qualitative content analysis of the interview transcripts to identify cultural issues shaping digital dispute resolution practices. External validation of the analysis took place through an expert panel review. The findings show that culture affects the extend to which digital technologies can be used in dispute resolution and that the cultural position of a project team should be determined to ensure successful implementation of digitalisation to effectively improve dispute resolution practices.

It is well known that construction is one of the most polluting sectors worldwide. The nitrogen crisis has led to the suspension of numerous projects on multiple occasions in the past. We are also increasingly faced with scarcity of materials and the effects of climate change. Therefore, it is time for change, a transition towards more sustainability in construction. This thesis specifically researched the offshore energy sector where the Dutch and German Transmission System Operator (TSO) is enabling the transition to a more sustainable future by employing partnerships.

This thesis contributes to the current debate on partnerships by researching how a partnership in the offshore energy sector should be set up to enable achieving sustainable objectives. First, a literature review is conducted followed by an empirical research using a single case study originating from the Dutch and German TSO TenneT called the 2GW program. Semi-structured interviews were conducted and followed by a thematic analysis. For the discussion, a form of discourse analysis was deployed, specifically the dialectical-relational approach.

The results indicate that the successful launch of partnerships to enable achieving sustainability goals within the offshore energy sector is currently hampered by several obstacles. The discourse analysis revealed three main obstacles: fear of the unknown, limited market competition, and challenges in implementing the partnership approach.

The conclusion offers a comprehensive roadmap that can be utilised by similar public clients in the offshore energy sector and with some adjustment in other sectors as well (where consideration of environmental factors is essential). The research recommends fostering market incentives to increase competition, promoting clear communication and education about sustainability goals, and encouraging a cultural shift within organisations to embed sustainability into their core values.

The Dutch government aims for a fully circular built environment by 2050, transitioning from a linear to a circular economy. This involves establishing construction hubs, divided into circular hubs (focusing on closed-loop material chains) and non-circular hubs (focusing on efficient transportation). Currently, only a small fraction of construction and demolition waste is reused, making the role of circular construction hubs crucial.

This study investigates how to stimulate the realisation of urban mining hubs in the Netherlands. The primary research question is: How can the realisation of urban mining hubs in the Netherlands be stimulated? Data was collected through a literature review and semi-structured interviews with key stakeholders in the construction sector.

Findings highlight the undefined role of hubs within the urban mining process and the advantages they offer, including resource conservation, financial savings, and employment opportunities within a circular economy. Barriers include insufficient material supply and demand, inventory uncertainties, and inadequate legislation. An actionable framework was developed, consisting of three phases: initiation, optimisation, and expansion, with a focus on innovation, education, and collaboration among stakeholders.

Circular procurement has been found unsuccessful in two-thirds of the cases. Literature indicates that Systems Thinking (ST) is required to boost the transition to a circular building sector. This study focuses on the Initiation and Definition (I&D) phase of building projects. Currently several barriers impede the incorporation of circular ambitions in this phase, the study aims to develop a set of intervention strategies that can be used by Project managers (PMS) to overcome the barriers. ST is used and its contribution is evaluated. The research question address is “How can systems thinking contribute to the development of intervention strategies for the incorporation of circular ambitions in the initiation and definition phase of a building project?”

This is a Research through Design study, in which a Causal Loop Diagram (CLD) reflecting the process of incorporating circular ambition in the I&D phase is developed as an artifact. This CLD is used to gain insights in the dynamics in this process and to formulate intervention strategies.

The study begins with a search into the current barrier to circularity in the I&D phase making use of semi-structured interviews. It commences with the development of the CLD and formulation of intervention strategies in three sessions with a focus group. These results are discussed in semi-structured interviews with practitioners who were not involved in the focus group.

A total of twenty-six barriers were identified. The most cited barriers are the expected higher investment required for circular approaches; current financial models that are not organized for circularity and predetermined budgets that do not consider circularity. In the developed CLD six (6) themes were identified: certainty, knowledge, innovation, budget, materials, and courage. Based on this model eight intervention strategies were formulated.

Five (5) out of the eight (8) intervention strategies are related to knowledge and knowledge sharing, indicating the importance thereof. Although the initial hypothesis suggested that through ST different intervention strategies would be formulated compared to event-based thinking, the findings showed limited differences between the two. However, ST proofed valuable in improving the understanding of the dynamics and challenges in incorporating circularity by making mental models explicit and facilitating communication. Key insights highlighted the central role of ‘experience’ in improving the incorporation of circularity in the I&D phase. ST can also be used as a discussion tool among practitioners. It will help to explore circularity and surface underlying problems that impede the uptake of circularity.

Projects are becoming larger and more complex, resulting in work being done more in a team environment. Among other industries, the construction industry is project-based as well. For the successful completion of construction projects, inter-organizational teams consisting of representatives from the owner, designer, contractors and other stakeholders need to cooperate. Due to the numerous relationships between the various organizations, construction management faces great challenges. One of these challenges is the encouragement of information sharing. Thus, information sharing in inter-organizational projects has already concerned academia for a long time. However, knowledge of how information flows during the design life-cycle is still limited, and no study has been found to examine that by using social network analysis.

Therefore, this research adopted social network theory to study information flows as its main research activity. By gathering data through a survey and analysing them by performing social network analysis, it was possible to map the communication network of the inter-organizational venture by creating sociograms and extracting some key metrics that would give meaning to these. In parallel with the social network analysis, some participant observations added a qualitative character to how information flowed between the teams. However, these two research activities were insufficient due to some limitations this study was subjected. Thus, the results from the already mentioned research activities were enriched by hosting an expert panel where the experts invited could provide further insights into the networks’ formation.

This research concluded that in the predesign phase, there should have been more involvement from teams that were generating valuable information to balance the control that the most influential team, according to the SNA, had over the flow of information. The different design teams should have had the same degree centrality and probably the same betweenness centrality. However, it may also be the case that one area is more complex and more information-dependent, thus ranking higher in terms of influence in the network. In the definitive design phase, team Management Design & Integration should control the flow of information. However, other teams should also support it since being the only one to have control may become a bottleneck or even a single point of failure. Such teams could be teams of the same subculture regarding their roles and responsibilities in the organization. In the execution-ready design phase, many central figures concerning the construction-related teams exist in the network since many activities take place. There are multiple sources of information; thus, team Management Design & Integration should be able to absorb all of it. Attention must be paid to the various barriers that have been found to impact how information flows. Especially in how the information is being communicated and how to motivate employees to use the various technological developments available since they found to enhance information sharing.

Any industry is focusing on creating an environment that is as safe as possible for everyone that is involved. This is no different for the construction industry. However, the construction industry is placed second in the ranking of most dangerous industries. The Dutch Safety Board, being an independent administrative body, has recommended to integrate a third party into the contractual general terms and conditions such as the UAC for integrated contracts. The objective of this research is to examine whether there is any potential to integrate a third party into the UAC-IC 2005 contract. This potential is being examined using a comparison between the UAC-IC 2005 and FIDIC Yellow Book 1999, a contract in which a third party is already present. In this comparison, the main focus points are the "vital tasks & responsibilities" that are necessary in order to safeguard safety on site, safety of the surrounding area & structural safety.

This thesis has found that the three types of safety can be improved if the vital tasks & responsibilities are properly performed. These tasks & responsibilities mainly relate to the management of project specific and safety related risks, and to the safety approach that is a result of this risk management system. From a theoretical point of view, the UAC-IC 2005 and the Dutch Building Decree are able to facilitate these vital tasks & responsibilities. The ON is responsible for most of the vital tasks & responsibilities, and the OG has the possibility to use an external control mechanism to verify this. The practical situation is however different. It is not uncommon that other aspects like time, or money can get more important for the contracting party than proper risk management processes and the corresponding safety approach. Work is not executed as intended, but rather as work-as-actually-done. The OG’s incentives in the UAC-IC can be insufficient for him to effectively perform this external control mechanism. This leads to a possible situation in which no internal nor external control mechanism is present, which is to the detriment of safety. The Engineer, being the party that is responsible for an external independent control mechanism in the Yellow Book’s quality assurance system, does have more incentives to actually make him perform this external independent control mechanism effectively. This incentive has its origin in the uncapped liability which the Engineer can be held liable for. If the Dutch version of the role of the Engineer would be integrated into the UAC-IC, he would be able to improve the three types of safety when he takes over the responsibility for the external control mechanism from the OG under the assumption that this external control mechanism will be performed more effectively. This assumption is valid if the Dutch Engineer would have a comparable liability as in the White Book. Since TNR 2011 would most likely be used in the Dutch construction industry, the liability in TNR 2011 must be increased for Dutch Engineers in order to be comparable to FIDIC’s White Book.

Better collaboration in the construction industry might lead to a more efficient construction process and a high reduction of failure costs. A model that tries to support collaboration, is a Bouwteam. In a Bouwteam, the contractor is already involved in the design process and shares his knowledge about the realization costs of the design and its execution. This makes it possible to design more cost-consciously and reduces the chance of adjustments during the execution. Although a Bouwteam offers many advantages, practice shows that collaboration within this model can still be improved. Several researches have been conducted about the collaboration in the Bouwteam phase, where client and contractor work together. However, no research has been done about the phase thereafter, the transition from the Bouwteam phase into the execution phase. Therefore, this research focuses on how client-contractor collaboration can be improved during the transition from the Bouwteam phase into the execution phase in a Bouwteam project.

During construction projects, multiple stakeholders collaborate in reaching project success. To determine success - a subjective perception of the 'current' state-of-affair - stakeholders align their interpretations of what is valuable during assessment processes. A framework was developed which helps in making values explicit during these assessment processes and helps to facilitate meaningful conversations about values.

This research discussed circularity and gave a proper definition for this for the Dutch water boards. This research developed an implementation tool that can be used by the water boards. It shows which design criteria exist within the core measurement method of cb23. These design criteria consist of 7 indicators. It is advised to use these indicators as circular ambitions for the water boards. These indicators can be measured over time, in which the water boards can effectively steer and measure these ambitions. This research showed 42 circular strategies, which have been connected to the ambitions of the CMM through an implementation tool. Strategies are connected to one of the 9 life cycle stages of an asset. These strategies, however, can conflict which each other. For example, solar panels might generate green energy, but if the alloys used can not be recovered, this results in a valuable loss of scarce materials. Moreover, some strategies are dependent on other strategies or can create synergy. An overview of these interactions is provided.

In order for the construction industry to be climate neutral and circular by 2030, a transition is needed that changes norms & values and the way of working. Within the construction industry 80% of the clients are public organisations, which can steer a sustainable transition by posing a demand for sustainable alternatives. In order to stimulate this, the Buyer Groups have been initiated. The Buyer Groups, consist of a small network of contracting authorities, who together formulate a shared market vision for a specific product. This, to create a strategical focus on sustainability, make clients responsible and to harmonize the demand. The research question of this qualitative and explorative research is: 'How can Buyer Groups effectively influence relevant construction sub markets towards a climate neutral and circular construction industry in 2030, with a harmonized market vision?' In order to answer this question, innovation dynamics within different sub market, the requirements for an ambitious and feasible market vision, a contributing market consultation and a suitable design of the Buyer Groups, were being investigated by a literature study and case studies. The objective is to support future Buyer Groups in contributing towards a sustainable construction industry. Within this research three different types of construction submarkets have been distinguished, which all have another relationship with their clients. This relationship determines another focus for the market vision and market consultations. Besides, the transition phase a market is in, also influences the appropriate focus of the market vision and market consultation. The biggest remark to this research is that the real effectiveness of the Buyer Groups and their market visions have not been measured yet, because the market visions are about to be implemented.

This research aims to overcome risk aversion by optimizing the allocation of risks in projects procured through an Innovation partnership. The research question answers: How can an Innovation Partnership stimulate innovation in the construction industry by dealing with uncertainties related to product innovation? The relevance of this research lies with the need for innovation in the construction industry to meet future sustainability and circularity goals and to renovate and replace existing infrastructure. However, due to the novelty of innovation, more uncertainty is introduced in a project where innovation is included. To stimulate innovation through an Innovation Partnership, the contractor and the contracting authority should manage the uncertainties related to product innovations following the level of uncertainties of the product innovation in the specific project stages. The level of uncertainty surrounding a product innovation reduces after the R&D phase of the Innovation Partnership. Therefore the contractor and the contracting authority should distinguish a difference between the R&D phase and the execution phase of an Innovation Partnership. It is recommended that when the contracting authority procures a project through an innovation partnership (1) they minimize the number of specifications and state the specification functionally to utilize the innovativeness of the market. (2) Stakeholders should be engaged in the project early on to overcome the resistance of stakeholders that are not ready for innovation. (3) The risks during the R&D phase should be managed by a design alliance. (4) The execution phase can be governed by an UAV-GC for the general project. In addition, an alliance module should be added for the risks related to the product innovation.

The European Union’s incentives to make a shift from a linear towards a circular economy has pushed researchers to come up with tools that will facilitate this transition. A material passport is a digital tool that stores data regarding general information, the composition of the material and its properties. The passport is deemed as active at different stages and data regarding the condition of the material should be updated accordingly. The scope of the research is to investigate the division of tasks amongst stakeholders that have a responsibility in collecting and storing the data throughout different project delivery methods for the Infrastructure and the Real Estate sectors in the Netherlands. The aim of the research is to come up with a new setting of arrangements that shows a clear division of the responsibilities, hence promoting the safeguarding of data in a material passport.

Responsibilities have been assigned to actors and stakeholders throughout different project phases based on the tasks at hand to cover the full spectrum: from Producer to Demolition and Recycling phase. Literature studies and explorative interviews allowed for the framework to be developed under a RACI (Responsible, Accountable, Consulted and Informed) matrix. Mainly, two approaches have been developed:
• The Centralized approach to store the data centrally within the organization/party ensures that each organization comes up with its tailor-made passports according to their own goals and needs for re-use.
• The Supplier approach that entails keeping the data with the Supplier. Each supplier will be able to determine what information is necessary to collect for their own production and hence promoting the potential re-use of the material.

According to several criteria and limitations assessed, results have shown that the Centralized approach is incentivized to be used in the infrastructure sector. The end responsibility lies with the most profitable party, the party that has the best interest in keeping the information centrally in accordance with their way of working, which remains with the Lease holder/ Asset owner. Moreover, the Supplier approach was deduced to be best applicable in the real estate Sector. End responsibilities is best with financial parties (banks, insurance companies) in order to maintain the value of the asset as a collateral (Onderpand) until the building is eventually decomposed. Recommendations for the application of the framework is through contractual agreements. Special agreements could pave the way for the initial setting of the division of responsibilities, however, changes are recommended to the procurement law for the long-term applicability of passports.

Currently the world is dealing with a pandemic. The world has stopped, and people are distancing from each other. However, this large crisis is not the only crisis the world is currently dealing with. Climate change is affecting the world drastically since the last century. Our current way of development must stop to deal with this change. This is the ideal time to stop and think about the future. How can we provide a future-proof city that is still attractive to our grandchildren?
Regardless of the crisis, more people want to live in cities, and therefore more features are needed within the same space. Cities must continuously adapt to new needs and demands. This fast-changing environment makes it even harder to continue our current development, while adapting to the needs and demands. A future-proof city starts with a sustainable development of new plans. It is time to improve the involvement of sustainability in area development. This study will look at this overdue change in area development. It acknowledges this problem and aims to advice how sustainability can be better embedded in spatial planning.
To support this optimization, the instruments of a municipality are researched in this master thesis. Next to the instruments, also, governance and the organizational aspects are included. This research has found that these three aspects of instruments, governance and organization combined should be optimized. An optimization of these three aspects can ensure that an area is developed sustainable.

Rijkswaterstaat is a governmental institution that is responsible for the management and development of the Dutch main roads, waterways and water systems. A DBFM contract is a contract in which the aspects of designing, financing, constructing and maintaining a construction project are integrated. The contract is long-term and based on delivering a service instead of an asset. This research is aimed at the period of time in the contract after the construction is completed which is called the exploitation phase. To make sure that the service is delivered according to the standards, the client has formulated functional output specifications. In order to check whether these functional output specifications are met, the performance of the contractor is monitored. This monitoring of the performance is processed into the payment mechanism. If by monitoring it turns out the functional output specifications are not met and thus the performance is insufficient, this has financial consequences for the contractor. After finishing the construction, the contractor receives an availability payment of Rijkswaterstaat every quarter of the year. The gross availability payment is the maximum amount that the contractor can receive. The contractor will receive this amount if no discount is imposed. There are two different discounts that can be imposed by Rijkswaterstaat: the Availability Discount and the Performance Discount. The Availability Discount has a direct link to the payment. There is no debate possible on the Availability Discount. The Performance Discount has an indirect link with the payment. The contractor can approach the Contract Manager of Rijkswaterstaat to discuss the Performance Discount. If the contractor cannot meet certain specifications, penalty points can be imposed by Rijkswaterstaat. The specifications in the contract indicate what amount of penalty points are to be imposed in the occurrence of shortcomings by the contractor. The Contract Manager has the authority to decide on imposing penalty points. It is known that not every shortcoming according to the contract ends in penalty points. It is unknown how the approach of a Contract Manager can influence the penalty points that are imposed. Different reports state that managers argue that this has to do with the culpability of the shortcoming. How do Contract Managers make this decision? What is their approach? What influences that approach? The political management calls for uniformity and standardisation, while the Contract Managers are afraid that this will come into conflict with the culpability and proportionality of the penalty points and that this will have a negative impact on long-term cooperation (Court of Audit, 2013; Rijkswaterstaat, 2017b; Tweede Kamer der Staten-Generaal, 2017).
The relationship between Rijkswaterstaat as client and the private party as contractor is related in the study to the relationship between principal and agent that forms the basis for both the Agency and the Stewardship theory. These theories are used to generalise and clarify the findings. This principal-agent relationship is characterised by the information-asymmetry between both parties. The exchange of information between the client and the contractor is incorporated into the research. The main question of the study is as follows:
How do the Agency and Stewardship theories clarify the influence of information exchange between clients and contractors on the approach of Rijkswaterstaat Contract Managers when imposing penalty points in the exploitation phase of the DBFM contract? The first phase of the research was completed through a literature study and a preliminary research. This preliminary research consisted of studying the internal Rijkswaterstaat document and informal conversations with Contract Managers. This phase ended after the design of a theoretical framework and is followed by the empirical research. This was done through a case study. Four projects were selected for the case study. The Contract Managers of these projects were interviewed. The theoretical framework serves as a tool to analyse and visualise the relative position of the projects. The collected knowledge has been analysed in order to discover interdependencies in the characteristics of the projects in terms of the perspective on the penalty points regime, sharing information and the approach of the Contract Manager. The last part combines all aspects of the research in which the validation, discussion, conclusion and reflection of the research are presented.
The Contract Manager is part of the Integral Project Management (IPM) team that is responsible for managing one or more infrastructure projects of Rijkswaterstaat. The Contract Manager must ensure that all parties to a contract fully understand their respective obligations and possible shortcomings. The requirements are laid down in the contract by managerial actors. In order to understand these requirements and to assess the outcomes, the Contract Manager obtains knowledge and information concerning the profession. The Contract Manager is located between these managerial actors and the profession. This position relates to the actor that ‘can both play the managerial game and understand the profession’ and is defined by De Bruijn (2006, pp. 90–91) as a boundary spanner. The process of imposing penalty points starts with the observation that a performance requirement is not met. This can be observed by an individual or by a computer system. In the case of a deviation that is worth penalty points, this is a shortcoming on the part of the contractor. The shortcoming is then registered in a system. Ultimately, a decision will be made on whether to impose penalty points. There are three different outcomes: penalty points are imposed, penalty points are placed on hold and the contractor formulates a control measure or no penalty points are imposed. If the control measure is not met, penalty points can still be imposed. The decision to impose penalty points relates to governance through monitoring and incentives described in the Agency theory. The decision to put a penalty point on hold and to have the contractor formulate a control measure relates to governance by means of empowering structures described in the Stewardship theory. The Contract Manager has the authority to make this decision. The Contract Managers make this decision based on the ‘Stramien Boetepunten’. The ‘Stramien Boetepunten’ is a guideline and not a legislation. This guideline is an attempt to describe the tacit approach of the Contract Managers and takes into account the nature of the requirement, the culpability of the shortcoming and the proactivity of the contractor. Culpability and the proactivity of the contractor can often be interpreted in different ways and is subjective. Although imposing penalty points is discussed in the IPM team, one Contract Manager can make different decisions than the other. The results of the research give a suggestion of a number of interdependencies. The research suggests that a Contract Manager who is closer to the profession obtains more nice to know-information, which reduces the demand for need to know-information. This Contract Manager has higher levels of trust and prefers to have a control measure formulated. Higher levels of trust and the preference for a control measure relates to the shareholder described in the Stewardship theory. Lower levels of trust, demand for monitoring, focus on the result and choosing to impose penalty points relates to the principal described in the Agency theory. However, the scope and history of the project influence the results of the research mentioned. A Contract Manager on a project with a smaller scope has fewer intermediate links that increase the distance between Contract Manager and the profession. In addition, Contract Managers can include past events in their decision. The problem definition showed that politicians value optimal follow-up of the contract. However, the research shows that the degree of discretion is regularly used by the Contract Managers to deviate from this. This is substantiated by the importance of a boundary spanner. By means of the ‘Stramien Boetepunten’ the Contract Managers attempt to guide their approach as a collective in advance of the decision on imposing penalty points. In order to reduce the risk of losing important information and to get a complete overview of the state of affairs, it is recommended to start collecting the information on imposing penalty points centrally.

The risk allocation in DBFM projects is currently a hot topic, whereby multiple contractors have withdrawn from the procurement of these projects. This research provides a practical guidance in the risk allocation process of DBFM projects, consisting of design principles of literature and lessons learned from practice. The design principles that should be taken into account are: The party has the best capability to control the events that might trigger the risk; The party has the capacity and expertise to control, monitor and minimize these risks; The party has identified, understood and evaluated the risk; The party has the resources to deal with the risk if it fires; The party accepting the risk can charge the right premium for this risk; The party has the right risk attitude and wants to accept the risk. The lessons that can be learned from practice are to use the insights of similar projects, to have a proper allocation of data inadequacies, to have an open discussion on the risk allocation in the procurement and to focus on collaboration. Besides the practical guidance, this research has provided an assessment framework in order to see if it is (un)favourable to use the DBFM contract. The assessment framework is based on three characteristics, namely the involvement of only one discipline, the budget between the €60 million and €500 million and the stable scope over time.

Public construction projects have an image of poor performance, both in the Netherlands and other countries. Too many public projects go over budget and over time. A possible improvement to this poor performance could be Early Contractor Involvement (ECI). ECI literally translates to involving a contractor “early”, which in current practice implies that the contractor is involved before the design phase. As a more unambiguous definition was missing for this principle in the Netherlands, this research identified two varieties of ECI; a consulting form (like a market consultation) or a contracting form, where the contractor is contracted during the final stages of the initiation phase. ECI is suggested in literature to be a promising option to improve public construction projects in the Netherlands, but literature is split on what ECI is and what the benefits are. This thesis study aims to identify the effects, implications and implementation of ECI in the Netherlands. From this study, eight potential benefits of ECI have been identified by means of a Delphi study. Some examples of these benefits are improved risk assessment, risk distribution, higher project quality and higher certainties in both costs and planning. However, reaping these benefits requires preparation and experiments with projects using ECI. There currently seems to be no initiatives with ECI on the agenda, except the refurbishment project of the Hoevelaken intersection.
To implement ECI in the Dutch public construction industry, this research found several conditions to implement and use ECI. Firstly, the role division of the client, design firm and contractor should be done differently. Secondly, the distribution of the risks must change. And thirdly, procurement may have to be specifically designed for ECI. In addition to these conditions, there are three barriers to overcome. These barriers are primarily concerned with the client side of the market. The client fears the early commitment to just one contractor and finds it hard to secure the competition in the market properly when ECI is used. Following these two barriers is a third; there is a lack of determination to experiment and implement ECI. To help overcome these barriers, four incentives are identified to be applied simultaneously:
• An investment from the public sector to experiment with ECI,
• Design of a proper exit-clause to terminate the contract,
• The use of Past-Performance criteria for procuring projects with ECI,
• The application of incentives on contractor behavior.
When ECI is implemented in public construction in the Netherlands, ECI will have implications on both public construction projects and the construction industry. In procurement the criteria other than price are likely to become more important, as price is unrealistic to test on so early in a project. Contractors will have to develop their advising role and expand their designing/engineering capacity. As their expertise and capabilities develop, design and engineering work is likely to flow from the design firms to the contractors. The engineering expertise of the client must expand as well, to be able to communicate on the same level as the contractors to prevent communication errors and opportunistic behavior.
This research suggests that ECI can indeed improve public projects on several aspects, but if there are too few experiments to develop and improve the concept it is unlikely to see implementation soon. As communication, perseverance and determination are key in experimenting with something new, this thesis advocates investing in ECI experiments with people who are capable and willing to try to make ECI work. Proper preparation and learning from the experiments will create forward momentum. When forward momentum is gained, ECI could be disproved to work or be proved a working innovation in the construction market, marking the next market improvement on the road to collaboration in the construction industry.

The last couple of years the concept of the Circular Economy (CE) has been gaining more and more attention. The Netherlands want to become a CE as well and the government presented a national policy programme including goals to reach a CE in 2050. One of those goals is that Dutch public authorities should procure all their projects 100% circularly by 2030. Practice shows that in the infrastructure sector public authorities start with high circular ambitions, but throughout the procurement process it seems to diminish. Public authorities tend to specify their need in detail, and make little use of the knowledge and experience that is present in the supply chain. The fact that the circular ambitions are only partly reached after the realization of the project makes the public procurement process not very effective. A possible contribution to increase this effectiveness can be a specific procurement approach that focusses on utilizing the experience from the supply chain, called the Best Value approach (BVA). However, no literature so far has described the opportunities of the BVA as an approach to procure circular infrastructure in the Netherlands.

The goal of this research is to create a guideline for Dutch public authorities about how they can procure circular infrastructure more effectively by making use of the BVA. This results in the following research question: In what way, if any, can the Best Value approach contribute to the effectiveness of public procurement in order to stimulate the transition towards a circular infrastructure sector in the Netherlands?

The infrastructure gap is defined as the gap between investment requirements of infrastructure and the public funds available. Due to these gaps, not enough new infrastructure is developed and this puts a constraint on economic growth. This study looks at the impact that pension funds can have on closing this infrastructure gap, and thereby aid in an increased development of new infrastructure.