Cost overruns and delays remain quite challenging in large construction and infrastructure projects. These challenges are partly due to the failure to properly identify and quantify second-order effects of risks. Second-order effects of risks are the indirect impact of a risk that can disrupt the overall project schedule and can cause a project to go over budget and run out of schedule. This research highlights the need to better identify
and quantify second-order effects of risks in the design phase of construction and infrastructure projects, where a new methodology is developed that can help in this regard. The research method used, the Double Diamond Design process model, starts with an extensive literature review and semi-structured interviews with experts in the field to clarify the definition of first-order effects and second-order effects of risks and analyse
their current handling. The newly developed method focuses on cascading risk mapping, (dynamic) vulnerability analysis, exposure to risks, probabilistic assessments and Monte Carlo simulations to better predict project outcomes. The new method has been validated by an expert panel, showing that it improves the identification and quantification of risks, although its complexity may require additional training and time
for implementation. This research aims to improve the accuracy of cost estimates and project planning by incorporating second-order effects of risk into these processes. The developed method, while promising in improving the accuracy and clarity of risk management, needs further testing to evaluate its practical efficacy compared to current practices.

Climate change has an enormous impact on our society: heat stress, droughts and flooding can cause a lot a problems. These problems are even more severe in the built environment as the urban design influences the urban climate. Less greenery, more paved surfaces, less urban ventilation an more human activity influence the urban climate in a negative way. This results in higher temperatures and more precipitation in cities compared to rural areas. To cope with the urban climate problems climate mitigation is not sufficient. Therefore it is also important to adapt the urban landscape to the changing climate conditions. Climate adaptation strategies for the built environment are still not sufficiently implemented and therefore this research looks at possible bottlenecks for these strategies in the spatial planning process.
In this research three Dutch post-war neighbourhoods are reviewed as they have seen recent redevelopment of (parts of) the public space. Post-war neighbourhoods are relevant as a lot of infrastructure is in need of replacement, which makes this an opportunity to combine this with the implementation climate adaptation. Post-war neighbourhoods are common throughout Dutch cities and also house relatively large amounts of vulnerable groups of people. The amount of public space in these neighbourhoods gives municipalities a lot of influence on urban design and thus on the amount of climate adaptation.
The research reviewed the spatial planning process of the three cases with twenty interviews with practitioners in the redevelopment projects and through the analysis of project documentation. The three cases are Bernadottelaan (Utrecht), IVORIM (Haarlem) and Kruidenbuurt (Tilburg). Main bottlenecks of climate adaptation are the large investment and maintenance costs and the claim on the limited public space. The goal is to come up with recommendations to improve implementation of climate adaptation in the spatial planning process.
The outcome of the research is that there are six different recommendations related to actor involvement, project finance, project scale and design guidelines. Maintenance parties should be actively involved in the design process instead of only giving advice or testing designs. This would enhance the amount of climate adaptation as measures have to be maintainable. Early contractor involvement is necessary to be able to be more cost efficient and come up with practical design solutions. External parties like housing associations and public utilities should be informed in the early stages of project for them to be able to match the planning. This makes bundling of challenges possible and eliminates some spatial restrictions. Project finance has to be integral as climate adaptation is divided over several departments. With integral financing projects can be bundled and therefore overall be more cost efficient. Projects at neighbourhood scale benefit from the ability to solve different problems at larger scale and form the placement of solutions to other challenges so that climate adaptation measures can be done where they are needed the most. Design guidelines need to be implemented to ensure that ambitions and priorities are rationally translated and balanced in the final design.

Public participation is crucial for achieving ambitious societal goals, including housing expansion, emissions reduction, mobility accessibility, and climate resilience. However, satisfying diverse stakeholders becomes increasingly challenging as projects become more complex. The Environment and Planning Act (Omgevingswet) in the Netherlands aims to streamline permit processes and enhance collaboration among stakeholders, emphasising public participation. This research investigates how public participation processes are shaped following the implementation of the act, focusing on the Oude Lijn and the HOV4 case study. Through 13 semi-structured interviews and 10 observations, the study examines organisational aspects, such as participation planning, coordination, transparent communication, organisational choices, mindset, and perspectives. Various effects such as influence, expectations, understanding, trust, efficiency, and representativeness are analysed. Findings reveal nuanced relationships between participation processes and effects, providing valuable insights for professionals seeking to understand and optimise participation processes. Understanding these dynamics is crucial for achieving effective and inclusive public participation, ultimately contributing to more sustainable and resilient infrastructure and urban development projects.

The construction sector significantly impacts the environment, with challenges including high carbon emissions, resource depletion, and waste generation. Renovating aging infrastructure in the Netherlands intensifies these challenges while presenting opportunities to integrate Sustainable Material Management (SMM). SMM focuses on optimizing material use across its lifecycle by reducing waste, improving recycling, and enhancing resource efficiency while balancing environmental and economic sustainability. This thesis explores how contractors can effectively implement SMM practices in Dutch infrastructure renovation projects. Through a structured methodology encompassing a literature review, semi-structured interviews with eleven industry professionals, and synthesis, the study identifies barriers, drivers, and actionable strategies for SMM adoption. Key challenges include financial constraints, client resistance, and limited access to sustainable materials. However, the study also highlights drivers such as regulatory incentives, technological advancements, and increasing industry awareness. The findings emphasize the critical role of contractors in promoting sustainability by influencing material selection, procurement processes, and construction methods. Recommendations include early contractor involvement in project design, flexible contracts to support innovation, adoption of digital tools like BIM and RFID, and collaboration across stakeholders. These strategies enable contractors to reduce environmental impact, improve economic performance, and align projects with circular economy principles. This research provides a practical roadmap for integrating SMM into renovation projects, supporting the Dutch construction sector's transition towards a more sustainable and resilient future.

This thesis examines the role of collaboration in water-adaptive urban development, focusing on the residential location selection process in the Netherlands. It identifies challenges in balancing housing demands with water and environmental constraints, exploring the Collaborative Governance model by Ansell and Gash (2008) to enhance multi-stakeholder engagement. Key stakeholders—municipalities, provinces, water boards, and developers—face power imbalances, inefficiencies, and conflicting interests, necessitating early involvement, especially of water boards, improved communication, and shared ownership. Strategies such as trust-building, shared goals, and both formal and informal interactions are highlighted, alongside the critical role of facilitative leadership in fostering collaboration. The study concludes with a proposed framework emphasising early engagement, institutional design, and leadership to enhance collaboration, addressing sustainable housing needs in water-sensitive areas and integrating key aspects of the Collaborative Governance model into the location selection process.

To prevent and reverse detrimental climate and biodiversity change, it is essential to motivate the housing construction supply chain to reduce the emission of carbon and nitrogen. The need to reduce the amount of emitted greenhouse gases and nitrogen oxides (NOx) is even more urgent in the Dutch housing construction. Currently, little research has been conducted into what hinders and motivates actors in the housing construction industry in their collaborative pursuit towards sustainable supply chain management (SSCM) in the Dutch housing construction industry.

The goal of this study is to provide new insights for actors in the housing construction chain, the government and science. To gain these new insights, the following research question has been formulated: How can the collaboration between actors in the Dutch housing construction industry be improved in the pursuit of sustainable supply chain management? This research was conducted through an in-depth case study research, based on literature research and semi-structured interviews with representatives from the most influential actor types in the Dutch housing construction supply chain. The housing construction supply chain contains a wide variety of actors with key players herein being main contractors, property developers and so-called first tier subcontractors

During the analysis of the interview results, an extensive amount of barriers and drivers were uncovered that actors encounter during the implementation of SSCM in the Dutch housing construction industry. For both barriers and drivers, it was found that subcontractors and property developers focus on the market and networking category, indicating they look more at the supply chain compared to main contractors. For main contractors, it seems they focus more on regulations, institutional barriers and drivers from within their own organization.

Based on the identified barriers and drivers, the following practical recommendations can accelerate the transition to SSCM in the Dutch housing construction industry. First, share knowledge with all actors in the supply chain. Second, develop a sustainable corporate culture that is reinforced both top-down and bottom-up in the organization. Third, some investments in sustainable operations are too high for a single actor to realize. Therefore, it is recommended that supply chain actors find effective ways to share financial burdens with each other in housing projects. Fourth and last, governmental institutions draft long term visions for the environment and subsequently translate this into policy.

The research findings can be used to inform and motivate main contractors, subcontractors, property developers and governments about practical implications and the use of policy instruments to achieve a sustainable supply chain in the Dutch housing construction industry. The combination of more intrinsic motivation from all actors in the housing construction chain can pave the way for creating a sustainable way of constructing houses.

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.

In infrastructure construction projects, stakeholder alignment is an important factor that contributes to project success and prevents excessive delays. Literature shows that it is known how to align stakeholders and what to do, however, when to carry out those actions, it not yet clear. This research contributes to that knowledge gap by analysing the Landside Infrastructure project of Schiphol as a single case study. Interviews with project stakeholders, project documents and field observations were used to collect data in order to develop a model.

Organizations in the construction industry are focusing more and more on sustainability. There exist various drivers and barriers (D&B) that can enhance or hinder sustainability in organizations. Research has so far mainly been focused on the primary activities within an organization. Hence, this study focused on the supporting activities (SA). This study researched what the defining moments are in the enhancement of sustainability in the SA of an engineering consultant organization. This qualitative research used the method process research, comprising a case study wherein processes of enhancing sustainability within one organization were mapped. Data for 8 cases was collected through semi-structured interviews and case documentation, within the playing field of the most important D&B. Case data was analyzed through the streams model of decision-making theory, existing of the problem, solution and participant stream. Furthermore, windows of opportunities (WOO) and tipping points (TP) were identified in the processes. The results include different patterns and striking observations. Most problem streams include CO2 emissions. The WOO involved raised awareness or multiple events making the problem more pressing. There were no significant TP identified throughout the cases. It was observed that awareness and intrinsic motivation form the most important drivers. The most important barriers are costs; the lack of support from employees or partners; and the lack of intrinsic motivation in the form of a lack of vision and priority. There were four most striking observations regarding the processes in the case study. The first observation is the intrinsic motivation of individuals playing a big role in the enhancement of sustainability. The second observation involves that the organization seems to hook onto trends and external events. The organization is only picking low hanging fruit, by making use of changes that are already planned or taking place, forming the third observation. The fourth observation comprises that there is a lack of clear goals, vision and priority regarding sustainability within the SA. It is therefore recommended to create a supportive and open environment for individuals that are motivated to enhance sustainability; to make use of external events, trends and of changes that are already lined up, but to not let these external occurrences determine the path towards sustainability; and to develop clear goals and a strategy for sustainability in the SA, for a more integral approach.

The positive relation between the performance of the client-contractor team and the end-result of a project has led to a growing attention for the human factor in construction procurement exercises. Over the last decade, assessments of constructors’ collaborative behaviour have been used more widely as a partner selection method. One of the most intensive forms of evaluation on soft parameters can be performed via an assessment (centre), also called workshops, with the tenderer’s and client’s team. The purpose of this explorative study is to provide more insights by 1) collecting the client’s motives to use these collaborative tender criteria, 2) identifying the different formats of assessments, and 3) learning lessons from projects that have conducted behavioural assessments. Ten cases are selected across the Netherlands, the United Kingdom and Finland, all of which focus on the procurement phase of a medium to a large-scale infrastructure project. Eleven semi-structured interviews with project and contract managers are used together with five assessor-interviews to gather empirical information. These independent assessors are involved by a public client to score the tenderer’s team during the assessment on a predefined list of sub-criteria. The thematic analysis shows that the use of collaborative criteria can be linked to the development of relational contracting and early contractor involvement. Especially in alliance and design team models with an integrated project team, a high weight is assigned to collaboration in the tender evaluation. Clients also aim to stimulate bidders to be more aware of collaboration and soft skills. The team assessment is applied for this purpose: it assesses the authentic behaviour of key figures that will be working on the project instead of only focussing on written bids. Results reveals that the assessment puts ‘collaboration’ high on the agenda of all parties right from the start, brings the team-related points for attention upfront, and stimulates bidders to approach team composition in another way. Nevertheless, several other instruments could lead to (some of ) the same goals and ongoing attention is needed to utilise the benefits of the assessment. Hence, the attitude and reflection of the client’s team is considered to be crucial for proper implementation. This study shows that the team assessment has proven to enable clients to make a more informed choice for a contractor on its collaborative behaviour. In this way, team assessments can fulfil the potential of being one of the instruments to facilitate high performing teams and project success.

By increasing the life-span of building products, the Reuse strategy has potential to reduce CO2 emission in the construction industry but it is observed that not many building products are reused because it is not economical. The government aims to overcome this issue by encouraging the development of reuse markets but it is not yet clear for which building products it is possible for markets to arise; how to determine whether a self-sustaining B2B market for reusing specific products can arise with government support is the main question of the research. From Exploratory interviews, it was found that there are several types of obstacles that make reusing building products uneconomical. Literature was reviewed in search for the effects of these obstacles on the costs of reusing but it turns out that literature on this topic is lacking. Because there is already tacit knowledge available from demolition contractors who disassemble and sell second-hand products in the B2C market, it is decided to focus on supply of second-hand building products in the research. A Theoretical Framework is developed to provide the metrics for answering the main question with a supply-driven approach. It is proposed that there must be a hypothetical middleman who buys second-hand building products from demolition contractors to temporarily store them and upgrade them in order to be able to provide products that compete with new products. The framework also contains a model that demonstrates which price E1 demolition contractors must receive from middlemen to make reuse feasible for them and whether a transaction is profitable when the price E1 and the middleman’s costs E2 are subtracted from the price that builders are willing to pay for the product. Another model then evaluates whether there can be a market size for which the total profit made from all transactions is large enough for the middleman to facilitate market development. It does so by proposing how the price E1 and E2 develop when production scale increases. In a case study about reusing toilets, a method is demonstrated for determining the prices E1 and E2 at different production scales. This method is referred to as the Market Assessment Method. The price E1, that demolition contractors need to receive for disassembling a product is determined for different situations where the product occurs by means of a newly developed tool referred to as the Purchase Costs Tool. This tool is synthesized on the basis of stories from 15 demolition contractors, gathered in semi-structured interviews. The tool is validated by linguistic analysis and by testing it in practice. The tool is considered the main deliverable of the research. The case study shows that it can in fact be determined whether a market for toilets can arise by using the developed method and tool. Based on the discussion, it is concluded however that focussing on supply alone is not enough to conclude whether a market may really arise based on the method because it is not realistic that a middleman can actually supply an old product in the same way as a new product. It is proposed to do follow-up research to the additional costs that a builder needs to make for reusing second-hand products. Although the developed method does not cover the entire scope, it is concluded however that the method forms a valid basis.

It is no secret that (asset)managers are currently dealing with a difficult task to maintain and improve the quality of their assets. The main reason for this urgency is the change of use and the end of lifespan of these assets. This is especially the case regarding the inner-city quay walls. These quay walls are usually owned and managed by local governments. The city of Amsterdam in particular has a tough task ahead of them. Approximately 200 km of quay wall need to be maintained or renewed of which the technical state is unknown. A vast majority of these inner-city quay walls are retaining walls on wooden piles. The absence of this information makes it extremely difficult for the asset owner, to determine the current technical state of their quay walls. The combination of limited information and time have shown in practice that quay walls can fail at any moment. To prevent this from happening a variety of intervention measures can be deployed to ‘extend’ the lifespan of the quay walls (short-term). Thereafter a systematic approach can be applied to rebuild or renovate these quay walls (long-term). However, the implementation of intervention measures is an overall complex task due to the densely built area and the stakeholders with divergent interests. This study provides an objective conceptual decision-making model to determine which intervention method is best suited for a particular location while considering the impact on the city, stakeholders and organizations. The research revealed six important topics which need to be incorporated in to the decision- making model. The topics were determined based on literature review, a case study and interviews. These six topics are: the critical cases (1), failure mechanisms (2), intervention measures (3), characteristics of the physical surrounding and the intervention measures (4), decision- making criteria (5) and lastly mitigation measures (6). Additionally, three decision-making moments are identified.

Since the introduction of Best Price Quality Ratio (BPQR) tendering, specific (non-financial) tender elements in the bid can also be decisive for winning the tender. These so-called qualitative aspects are therefore important means in the tender to distinguish a bid from competing bids. Although competition is believed to enhance a fair quality price ratio in the tender phase, this study points out that safeguarding the competition principle throughout the execution phase is not guaranteed. It turns out, added value of a measure in the execution phase, does not always coincide with the promised value in the bid (=misalignment). The objective of this research was to determine to what extent distinctive tender elements are aligned with added value during or after project execution for projects procured with the BPQR tender procedure. Besides, the aim was to define what underlying mechanisms in the BPQR tender process are causing eventual (mis)alignment. In this regard, the following research question has been drawn: What underlying mechanisms cause (mis)alignment between distinctive BPQR tender elements and the actual added value during or after project execution? Three research phases are being distinguished in this investigation: the exploration, the analysis (consisting of phase A and phase B) and lastly the synthesis. The exploration phase involved a literature study in which the aim was to gain full understanding of the theoretical aspects surrounding the topic of research. It was found that misalignment is mainly perceived as both disadvantageous for the client as well as for the losing bidders. As a result, the current focus is on alignment between tender and practice. This explains initiatives like SMART formulation of measures and the introduction of fines for non-fulfilment. Even new ‘out of the box’ ideas emerge like involving the losing bidders of the tender in auditing the execution of the project . All these approaches aim at maximising alignment, assuming misalignment would be disadvantageous for the client. The first phase of the analysis involved the analysis of the BAM Infra tender results. This analysis is used to create a general image of the tenders on which BAM Infra did perform outstanding and thus was able to distinguish itself. Furthermore, this analysis enables a proper selection of the tenders to conduct the case study research. The second phase of the analysis therefore explores the impact of quality aspects, bothin the tendering as well as in the execution phase of a project. This second phase involves a case study on four strategically selected projects regarding the distinctive character of the tender bid for each project. Subsequently, the study assesses how these elements turn out in practice, by conducting interviews with both the client and the contractor. The first finding is that measures can be divided in four quadrants: 1. Measure not implemented; effect not achieved (Q1) 2. Measure not implemented; effect nonetheless achieved (Q2) 3. Measure implemented; effect not achieved (Q3) 4. Measure implemented; effect achieved (Q4) Only measures in the fourth quadrant are examples of alignment, since in those examples both the implementation and the effect are aligned with the original promise formulated in the bid. Literature refers to, among other causes, strategic behaviour of contractors (adverse selection, moral hazard and strategic misrepresentation) as the cause of misalignment between tender and practice. The researcher did however identify four main causes for misalignment: Change of situation (A), enhanced / new insights (B), strategic behaviour (C) and bad luck (D). Subsequently, the total set of measures determining the distinctive character of the bid has been analysed. Resulting from this analysis, the researcher composed a categorization and a list of characteristics that measures can have. The categorization is both Mutually Exclusive and Collectively Exhausting (MECE) and it involves a distinction between process vs. product measures and temporary vs.permanent measures. Furthermore, the researcher did formulate seven characteristics. These characteristics are not MECE, which implies one measure can have multiple characteristics and the list might not necessarily be limited to the seven characteristics listed below. Ø Integral measures Ø Performance measures Ø Technical specification Ø Sexy measures Ø Beads (Dutch: Spiegels en kraaltjes) Ø Commercial-off-the-shelf measures Ø Multi-applicable measures Thereafter, the measures are mapped in the quadrants and subsequently analysed on commonalities. It was found that although their abundance in the set of most distinctive measures is roughly equal, product measures are more frequently implemented and more often achieve the intended effect than process measures. Furthermore, it turned out that measures that are not implemented whilst the effect is achieved, are always process measures. However, most process measures involved concerned situations in which the added value was absent. Besides, temporary measures are most coincide with process measures and, hence, score for the majority similar with these process measures (measures not implemented prevail). Temporary measures are less often implemented than permanent ones. Also, performance measures seemed to be the perfect measures in order to achieve alignment. Nevertheless, the room for distinguishing on this type of measures is questionable. But since the promised effect is very likely to be achieved by these measures, criteria of high importance of the clients could best be formulated as a performance measure. Commercial-off-the-shelf measures are preferred by contractors since they are easy to implement and are proven concepts. Yet, the clients state that these measures do not add value, since they would also have been conducted anyway. Sexy measures come with a large reputational risk for the client. This also relates to the responsibility public authorities have: generating public value. If public expenditures do not generate the value expected; public authorities will encounter social discontent. Based on the findings of this research, the following conclusions are drawn that answer the main research question: What underlying mechanisms cause (mis)alignment between distinctive BPQR tender elements and the actual added value during or after project execution? This research pointed out several causes for misalignment, of which strategic behaviour is one category. Strategic behaviour does however not dominate. It was however found that presumably, changes of circumstances are stimulating strategic behaviour of contractors. Issues underlying causes of misalignment are amongst others: multi-headedness of both the client as well as the contractor; lack of full-openness (of both parties) during the competitive dialogue and the use of inappropriate criteria to mitigate future maintenance costs in a construction contract. This results in misunderstanding, or a lack of (correct) information. In this respect it was learned that higher similarity in team composition (i.e.linking pin principle) between tendering and execution phase, can avoid loss of background information on important measures in a project. The research did also reveal that alignment is no holy grail. The focus on alignment not always generates value. Of the identified causes for misalignment, several cases are found in which fulfilment of the measure appeared to be disadvantageous for the client (!). This is especially the case when new insights occur and unforeseen added value appears. Yet, this study reveals that in those cases the specific measure involved often is not implemented. So, client satisfaction can also be achieved in case of misalignment. Although important, alignment is no cure for contractual discussions. A rigid focus on alignment may even have a negative impact on the provided added value for the client (and thus a negative impact on public value). Discussions whether measures are righteously implemented or not, consume time. And time – delay – means money. Given the fact that most clients are public bodies, this would involve loss of taxpayer’s money. In addition, rigid focus on alignment will put strain on the element of trust in the relationship between contractor and client, bringing the positive outcome of other future discussions in jeopardy. This reflection implicitly emphasises that a more externally focused value approach may have its advantages. Initiatives such as mixed client-contractor construction teams (Dutch: Bouw teams), that have an entirely different approach of project definition before the tendering phase, anticipate on that. In other words: currently the aim is to maximise internally focused value (=alignment of tender and practice) but in the end the evolving relevant issues all seem to indicate more externally focused value generating approaches in the future.

Currently there are a lot of contract types available for building projects. It is not always clear beforehand what type of contract a client should choose for his project. The goal of this study is to solve this problem by advising clients which type of contract to use for moveable bridge projects. Therefore, the following research question will be answered: How does the model look like that predicts which type of contract is best for a moveable bridge project? In order to answer this question, literature is studied and interviews are conducted to show which parameters and characteristics are of influence for this contract decision. This information is used to set up an initial model which advises what type of contract to use. This initial model is verified with the use of case projects in order to get the final model. Due to the wide range of building projects, this master thesis is focused on moveable bridges in the Netherlands only. Moveable bridges are multidisciplinary projects which makes the decision for a specific type of contract ambiguous. Making it the a perfect type of project to test the model. The literature and interviews highlighted eleven criteria that are of influence for the types of contracts incorporated in the model. The contract types that are included in this model are: RAW-bestek, Design & Build, Design, Build & Maintain and Turnkey. The decision to incorporate these four contract types is based on the fact to include traditional and integrated contracts. RAW-bestek is the traditional contract type that is common to use for moveable bridges in the Netherlands. The choice for an integrated contract form for moveable bridges is bigger. Therefore, integrated contracts with different ranges of integration are included. Starting with Design & Build as a conventional integrated contract form followed by Design, Build & Maintain as a more integrated contract form and Turnkey as totally integrated contract form. This initial model is verified with the use of four moveable bridge cases. For three of the case projects the model advised well. These projects went according plan and the advice from the model matched the contract that was actually used or the model highlighted the main headings for which the different incorporated contracts match the actually used contract. For example, case A used the contract type Engineer & Construct, this type of contract is not included in the model. The initial model showed exactly on which statements the Design, Build & Maintain contract and the RAW-bestek scored well for this case project. The statements on which they scored well are exactly the items for which an Engineer & Construct type of contract would be suited. If Engineer & Construct as a contract type would have been incorporated in the model, it would most likely be advised by the model. The verification of case B was not a match between the used type of contract and the advice from the initial model. The project did not went according to plan, but the advised type of contract would probably not have improved the situation. Several improvements are suggested based on comparison between this case and the other case projects. It is concluded that the model is functioning, based on the cases. However, it is recommended to extend the model with more types of contracts, such as the contract type Design & Construct, Engineer & Construct and Bouwteam. The second recommendation comes from the ambiguity concerning the benchmark score for the criterion complexity. The positive correlation between complexity and flexibility was stated in literature, meaning that when the complexity of the project increases the need for more flexibility also increases. However, other literature contradicted this; it was unclear which viewpoint should be preferred. Therefore, the decision was made to adopt the positive correlation for the initial model. After verifying this initial model, the benchmark scores for complexity were adjusted in order to be in line with the other literature. The advice from the initial model and the initial model adjusted for complexity were compared. However, based on this comparison no firm conclusion can be made about which viewpoint is preferred over the other concerning complexity. Therefore, it is recommended to further verify the model for the criterion of complexity. Furthermore, it is recommended to verify this model with more moveable bridges and cases for other types of projects in order to increase the validity, usability and applicability of the model.

The undeniable benefits of urban open spaces, such as parks and urban forests, has triggered a steady increase in “natural capital” demands. Nevertheless, the uncertainties surrounding open spaces and ecosystem services jeopardize their consideration in public decision making. Certain of their aspects are not fully translatable in economic terms, primarily due to the absence of proper valuation tools. This results in not only under-provisioning of natural capital, but also unsustainable urban development. Hence, an imperative need to incorporate efficient ecosystem valuation tools emerges. The objective of this research is twofold. Firstly, it aims to prove and quantify the influence of urban open spaces on the surrounding real estate’s market value. Secondly, it investigates which characteristics of these spaces bear the largest impact, with a particular interest in ecosystem services. The methodology employed in the present study is a combination of both quantitative and qualitative methods. The quantitative part, designated as Phase I, includes the establishment of a hedonic pricing model, which quantifies the added value of proximity to the selected clustered open spaces, which are also called “Ecosystem Service Hubs” (ESHs). The qualitative part, addressed as Phase II, swifts the focus from the housing samples to the ESHs. It consists of activities attempting an ecological profiling of the ESHs.
Phase I’s Hub Hedonic Pricing model revealed that ESH1 bears the largest influence on surrounding real estate, followed by ESH3 and ESH2. Notably, a 1% increase in distance would lead to approximately 2,7€, 0,8€ and 1,6€ per m2 for each hub respectively. Inserting the distance variable as a dummy variable, instead of a continuous one, displayed a similar behaviour. Thence, each housing sample is divided into categories in order to execute a distance effect sensitivity analysis. It is suggested that “young, large, row houses in greener neighborhoods” exhibit the largest distance decay effect sensitivity. Lastly, the overarching monetary values are roughly estimated. These are 5,81, 1,98 and 3,28 million € for each hub respectively, whereas the average value per m2 per house is 77,44€, 57,68€ and 107,47€ respectively. Concerning Phase II, the ESHs’ core components and characteristics are identified. Then, an association between the economic benefits and the core characteristics is attempted, through qualitative correlations. These are summed up in the following statement: “Ecosystem Service Hubs generate higher economic benefits when they are larger and more diverse, in terms of both composition and ecosystem services, with a significant sensitivity to recreational opportunities”.
This research’s findings could prove to be insightful for urban planning, since they could be applied in two major ways. Firstly, given an identified Ecosystem Service Hub, the development of the surrounding area could be adjusted to encompass primarily the optimal house and neighborhood characteristics. Secondly, given the “house composition” of a certain area, the optimal location and profile of a new Ecosystem Service Hub could be selected. In both cases, maximizing the value of surrounding real estate is achieved through optimal spatial configurations. In conclusion, the added value of urban open spaces is plural and reflects the use and non-use value derived from residents. This research’s rough estimation of an average of 80,86 € per m2 per house is an indication of this added value, subject, however, to the narrow scope of the study. Attributing this added value to particular open spaces’ characteristics could only be executed through qualitative correlations. In order to enrich the previous results, an integration of multiple valuation methods (social and ecological), which incorporate the various value dimensions, is recommended. More conclusive and definitive results will motivate planners to opt for polices revolving around ecosystem services and natural capital, thus, satisfying the steadily increasing demand.

The construction sector has rather poorly developed organisational learning capabilities (Styhre, Josephson, & Knauseder, 2004) and this results in lessons not being learned and applied in future projects. Lessons learned form the intellectual assets of an organisation and can help to reduce project risks (Carrillo, Ruikar, & Fuller, 2013). However, no lessons learned process has yet been developed for risk management. Furthermore, lessons learned processes can be ineffective because other variables can facilitate or hinder an organisation’s ability to learn lessons (Duffeld & Whitty, 2012). Facilitators positively influence organisational learning and barriers influence it negatively. This research is the first to is the first to study and determine the interaction of facilitators and barriers with the lessons learned processes and also to develop a lessons learned process for risk management. This research focused on filling these gaps in the known scientific literature. This has been done by combining these separate theories into a framework to address the practical problems that organisations in the construction sector encounter and to answer the main research question: how can the lessons learned of risk management be collected and applied in future construction projects?

The Netherlands is a low-lying delta and therefore prone to flooding. After the flood in 1953, the Delta Committee was established which commenced the Delta Works to enhance water safety for the society and economy. The Maeslant Barrier and Eastern Scheldt Barrier are the largest and most technologically advanced flood defences which are part of the Delta Works. These storm surge barriers shorten the effective coastline to reduce the risk of flooding within the Rhine-Meuse Delta and the Eastern Scheldt. However, the climate is changing and the risk of accelerated sea level rise increases. The problem is that the current storm surge barriers are not designed to withstand significant sea level rise. Sea level rise influences the hydraulic loads on the barriers which consequently increase the failure probability of these flood defences. International research argues that future sea level rise is much more uncertain than previously thought because of the instability of the West-Antarctic ice sheet. Therefore, it is critical to identify the degree of uncertainty of climate change and sea level rise to develop effective strategies for the storm surge barriers. This study uses a risk analysis to analyze the critical risk factors which could affect the performance and remaining lifespan of the Maeslant Barrier and the Eastern Scheldt Barrier. When sea level rise exceeds the tipping point of the storm surge barrier, the barrier fails to deliver sufficient water safety and adjustments are required to comply with the strategies of the Delta Programme. Therefore, this research has developed feasible and affordable solutions to increase the performance and remaining technical lifetime in case of accelerated sea level rise.

Current linear economic model entails coupling of economic growth with resource constraints and degradation of the Earth. In order to combat these negative aspects and to ensure prosperous and sustainable future, a new economic approach is emerging - Circular Economy. Besides neutralizing threats of the linear model, it also promises additional financial, societal and environmental benefits. This is recognized on (inter)national level with numerous action plans and legislation. However there are almost no actions that are aiming at implementing the notion of circular economy on the level of supply chains/ Therefore, inertia is observed in supply chains in relation to changing towards circularity. This thesis looks at the underlying reasons for this with the research methodology designed around the Social Network Analysis approach. Two main reasons for inertia in supply chains stemmed out of research: differences in perceptions of the actors within a supply chain and diffusion of responsibility phenomenon. Going one level deeper, four causes for these developments were uncovered:
1. Lack of incentives for companies in supply chains for making a change towards Circular Economy.
2. High uncertainties and risks that a change to circularity implies for companies in supply chains.
3. Lack of mutual interests between actors in supply chains for making a change towards circularity
4. Clashes of perceptions on all levels in supply chains, as well as between supply chains and government.

Sustainability is becoming an increasingly important aspect of the infrastructure industry, however, incorporating it has proven to be troublesome. As such, this thesis focussed on identifying success factors that influence the implementation process of sustainability from idea up to and including the tendering phase for public infrastructure projects.