Transitions related to climate change, energy and biodiversity affect spatial claims and require an integrated approach. These developments herald a redesign of the built environment. Consequently, civil engineering projects are changing from technological to integration-driven assignments and their complexity is increasing. These challenges manifest themselves particularly in the integrated design process.

Therefore, this dissertation focuses on the question of how performance can be improved by focusing on integration in the civil engineering design process. An optimal, integrated approach emerges as a critical factor. Additionally, the increasingly integrative, social and dynamic character of the civil engineering design process necessitates project team members to collaborate, connect and delve into the others’ interests. Therefore, empathy turns out to be a relevant factor for project success. Moreover, the empathic abilities of the Dutch civil engineering sector appear to be relatively low, implying room for improvement. @en

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

The existing high level of greenhouse emissions and raw material consumption are the current concerns in the infrastructure sector. On the other hand, the programs for renovating the aged and overloaded infrastructures are currently under progress as substantial national programs with circularity targets in the Dutch context, involving various public-private networks. Implementing the circularity strategy of re-use in conducting the infrastructure projects will be beneficial to reduce the amount of emissions, minimize the raw material consumption, and facilitate the formulated national programs. Currently, there are just a few re-use projects, and running a higher number of these projects and accelerating the re-use transition in the infrastructure sector are urgent topics in the global and Dutch context. Public client organizations (PCOs) have determining role in this regard, as owners and commissioners of infrastructure projects. There are wider networks of actors and extra stages to follow in re-use projects, which can create barriers and make the organizational aspects of these projects extremely important. Most attempts are locked at the tactical level of PCOs, and a gap has emerged between the tactical and operational levels of these organizations in the implementation of the re-use strategy, which prevents acceleration of the re-use projects. There is less attention in the current studies to the existing gap between the tactical and operational level of PCOS in conducting re-use projects in the infrastructure sector, the required procedures to fill that, and accelerating the re-use transition, which are zoomed in and investigated in this research. The research is conducted through a qualitative method, following three different phases of theoretical study, empirical study, and solution development in the context of a PCO. This research recognized that the existing gap between the two levels is rooted in different fields, and the most urgent ones have been identified. It revealed that tackling such gaps requires following specific organizational procedures by actors within each of the two organizational levels and between them. Following such procedures to deal with the addressed gaps can be easier through using a framework. The required framework, provided in this study for public clients including organizational procedures and their relevant re-use implementation factors embedded in certain categories. Among the existing gaps in practice, three gaps are recognized as the most urgent ones, which are placed in the two top categories of ‘culture, communication and behavior’ and ‘contract, manuals and guidelines’. The top three gaps addressed by three re-use implementation factors of ‘target formulation, follow-up & evaluation’, ‘internal & external communication’, and ‘collaboration with external parties’. The provided organizational procedures are interrelated in implementing the re-use strategy, and the result of implementing some procedures should be followed by the work of actors at the same or another level. The strategic level should also intervene to fill the gaps specifically in formulating and re-visioning the targets. Structuring the communications, collaborations, and target formulation stages through implementing the procedures recommended in the presented framework in this research, and consistency with that, will prepare the organizational context, and link the tactical and operational level of PCOs in implementing the re-use projects. As a result, the re-use activities at the operational level of public client organizations will be more structured. With well-linked tactical and operational level and structured re-use activities, the re-use transition will be facilitated and can be accelerated at the operational level of the public client organizations. To address a circular solution for the national programs of renovating infrastructures, the active networks in them can consider the networks as the national context for re-use transition, and customize the framework to structure the inter-organizational procedures between the involved parties in the tactical and operational transition levels. Through structuring collaborations & communications between tactical and operational parties, developing clear and detailed targets, and evaluating them, the re-use transition can also be accelerated on the national scale.

Construction projects have become increasingly complex, requiring effective management strategies to navigate challenges related to project contexts, interdisciplinary integration, and procurement processes. The Dutch Ministry of Infrastructure and Water Management (Rijkswaterstaat) has introduced the two-phase model to address these complexities. This model emphasizes client-contractor collaboration and differs significantly from traditional project management strategies. Emotional Intelligence (EI), particularly the competence of empathy, has been recognized as a valuable factor in improving collaboration and project performance. Additionally, Early Contractor Involvement (ECI) has gained international recognition as a project delivery model involving the contractor earlier in the project. ECI in the Dutch construction sector corresponds to the two-phase model of which the Bouwteam is a known example. This research aims to explore the role of empathy in improving project performance through client-contractor collaboration in the first phase of the two-phase model and provide a practical framework for practitioners. The research approach consisted of selecting four cases to conduct 16 semi-structured interviews. Qualitative data analysis software is used to research the research variables: empathy, two-phase model, collaboration, and project performance.

The research findings reveal two key relationships: the relationship between client-contractor collaboration and project performance and the relationship between empathy and client-contractor collaboration.

The relationship between client-contractor collaboration and project performance: the study indicates that client-contractor collaboration significantly influences project performance in the first phase of the two-phase model. Collaboration affects the actual performance of quality criteria and the perception of time and cost criteria. Key differences in the collaborative process within the two-phase model are a shift towards process-focused outcomes, shared responsibility between the client and contractor, and flexibility in criteria. Affective trust, communication, and cohesion are identified as crucial factors for successful collaboration. Tools such as Project Start-Up and team-building sessions facilitate collaboration and should be utilized to enhance project performance.

The relationship between empathy and client-contractor collaboration: empathy plays a pivotal role in facilitating understanding at the team member and organizational levels, fostering relationships, and promoting collaboration. It is particularly important in project phases where unfamiliarity between client and contractor exists. Empathy influences factors essential to the collaborative process, such as trust, communication, and cohesion. The research identifies factors that influence the occurrence of empathic behavior, including the work environment, team relationships, communication, and team size. A proactive attitude towards empathy and continuous development of empathic behavior are recommended for project success.

The research findings support the hypotheses that client-contractor collaboration and empathy positively contribute to project performance in the first phase of the two-phase model. A practical framework is proposed, consisting of four strategies, to improve project performance through empathy and collaboration. The framework should be applied collectively by project managers at the start of the first phase and throughout the project. Future research should explore quantitative testing of the hypotheses, validate the framework in practice, and investigate additional relevant competencies...

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

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

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

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

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

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

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

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

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

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

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

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

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

The rapidly growing infrastructure sector has a detrimental effect on climate change. The infrastructure sector is responsible for approximately 10% of worldwide emissions.
In the past years, sustainability became more important in the procurement of infrastructure projects. One of the ways to implement sustainability in infrastructure projects is by award criteria in the tender phase of the project, called EMAT criteria, which stands for Economically Most Advantageous Tender. In this way, the client or procurer can determine the added value of the quality per contractor. So, the EMAT criteria is a way of tendering through the best quality/price ratio.
Selecting a suitable subcontractor and supplier will considerably improve the professional services capabilities of the main contractor. Approximately 80 – 90 percent of large infrastructure projects are subcontracted. This means that to have a transition towards a sustainable sector, the subcontractors and suppliers must help too.
This research, therefore, aims to generate insight into how the EMAT criteria influence the selection of subcontractors and suppliers

A literature study and case study with three cases were performed in this research.
The results of the case study show that the EMAT criteria influenced the selection of subcontractors and suppliers, especially when it comes to sustainability. The EMAT criteria are an incentive for the contractor to look at the sustainability level and development of the subcontractors and suppliers. When the client asks for sustainability in the tender through EMAT criteria, the contractor will use sustainability as one of the selection criteria for subcontractors and suppliers. Moreover, the importance of the EMAT criteria (read the percentage of deduction of the tender bid) influence the trade-offs between the selection criteria as well. When the deduction for sustainability in the EMAT criteria is higher, the more important the sustainability selection criteria will be in the trade-offs for subcontractors and suppliers.

It is recommended to the client and the contractor to have dialogue sessions with each other about the measurement of the sustainable EMAT criteria and the responsibility for the monitoring of this. Making clear how sustainability is measured and what is needed to monitor it, will stimulate the contractors, subcontractors, and suppliers of the infrastructure sector to be more sustainable in the future.
Furthermore, the use of equally weighted sustainable EMAT criteria makes it easier for the contractor to select the most sustainable subcontractor or supplier.
A final recommendation towards the clients of infrastructure projects is that sustainability should be part of EMAT, or part of all present and future contracts in general if we are to achieve sustainability goals for the infrastructure sector, but mostly for the ambitious goals in the Netherlands.

Because of the potential consequences of sea level rise, decision-making to set adaptive strategies to handle the uncertainty over these consequences is required. There are several decision-making methods to deal with deep uncertainty and attempt to contain the impacts of sea level rise in organized response as the future unfolds. These methods are under development and need improvements to overarch challenges and strengthen the flexibility to work in different circumstances. Although each method has advantages that can be valuable and constructive in specific scopes, there are still future challenges and limitations concerning each method. Therefore, more research is required to widen the current focus and improve the applicability of the methods beyond the functional context.
Objective:
This study aims to provide a framework to improve decision-making methods by focusing on the decision context stage and the important aspects that must be considered by decision-makers at this stage. The decision context stage is the theoretical fundamental for the methods and a signpost to steer the whole decision-making process.
Questions:
The objective leads to the following research questions:
How to improve the decision-making context stage to deal with deep uncertainty in redesigning delta infrastructure?
1. What are the decision-making under deep uncertainty methods (DMDU) and to what extent do they consider uncertainty over sea level rise and future states of the delta?
2. What are the different functions of the Eastern Scheldt barrier system and how are they affected by the drivers?
3. What are the steps to improve the decision context for decision-making?
The resulting framework emphasizes the importance of zooming in to improve the context stage and integrate the life cycle management and shows an iterative way to improve the context stage in case of disagreement on the definition of success between different stakeholders and disciplines. Furthermore, the framework includes understanding the influence of drivers and the order of priorities to minimize uncertainty by integrating long-term planning into social and political contexts to avoid radical changes in the future. The study attempts to include these different steps in the context stage within other steps that already exist in the methods. The suggested steps can be considered as a trial to interconnect the infrastructure with the changing factors on the political, social, and economical levels. Redesigning delta infrastructure requires an integral approach to comprehending different aspects that play a role in handling deep uncertainty in the future.

An increasing awareness of sustainability problems urges the need for more sustainable practices within the infrastructure industry. Organisations actively engage sustainability in strategic missions and objectives. However, how these visions translate proactively to the tactical and operational levels of decision-making is still considered an exploratory area for the extant theoretical body of knowledge. Therefore, this research aims to support managers in tactical and operational decision-making for sustainability by means of a diagnostic research in the context of a long-term Strategic Partnership between client and contractor at Schiphol Airport. Their collaborative agreements based on Best Value aims for synergy by close cooperation between the partners and valuing professional expertise. To become highly committed to sustainability, organizations need to take responsibility over decisions regarding their organisational processes, in terms of dedication, motivation, and long-term investments to achieve effective solutions. Interventions require the direction of efforts into an organization-wide approach, meaning that both tactical and operational level management are internally aligned and stimulated to involve sustainability in their considerations. Also, a future directed mind-set and long-term investment approach are required to overcome technical and respectively cost related barriers. Fragmented decision-making can be overcome by engagement of stakeholders in sustainability ambitions. Moreover, proactivity in strategic partnering collaborations also requires extending responsibility towards supporting the partner’s responsibilities in order to achieve the best outcome for all parties involved. Therefore, it is key for both parties to allow each other to showcase their expertise within the set boundaries and ambitions of the Best Value principles. Currently, the client initiates new projects in which utility infrastructure projects play a role, whereas the contracting organization becomes involved after scope, budget, and planning are mainly determined. A mutually structured approach of formal meetings in the initiation process needs to be enhanced to collectively explore opportunities and define ambitions. Based on the gathered elements on proactive implementation of sustainability in decision-making levels, a conceptual framework is developed to test the case studies by analyzing sustainable outcomes in terms of their level of effectiveness. The analysis framework introduced by this study connects the different levels of proactivity with a chronological order of project phases, ranging on tactical and operational decision-making levels. This developed framework provides a practical solution for the collaborative setting between client and contractor, as it stimulates the development of mutual ambitions, substantive opportunities and directions for sustainable outcomes.

The Dutch railway system is the most intensively used in Europe. This fact, although fascinating, it creates complexity and many interfaces in its operation. The performance of such a system is governed by many aspects and involves many parties. Furthermore, these aspects and parties will have different needs and perceive performance in a different way. In order for the system to operate as smooth as possible, performance agreements are being made in different organizational levels. These agreements guide ProRail on how to manage the railway system and what it should achieve regarding several performance aspects. However, the railway system, as well as ProRail, are not single entities. They are comprised of several organizational levels. Each of these levels has its own needs and peculiarities, which in theory should be represented by their prescribed performance requirements. This creates a coupling between the performance agreements. They should be suitable for each organizational level while at the same time connected. These interrelationships can provide an overview of how the system performs and where adjustments should be made. Nevertheless, if their coupling is too strong, the organization can become cumbersome and stagnate. On the other hand, if their coupling is too relaxed, there will be no guidance and connection to what ProRail wants to achieve regarding the performance of the system. This thesis would like to examine the interrelationships between three performance agreements of ProRail. The Management Concession, Plan and its Performance Management System. The examination is focused on how well these agreements are coupled regarding different performance areas. Its proposed advice is a framework which can potentially alleviate the weaknesses described above. Its purpose is to strengthen the coupling of performance agreements while at the same time, leave enough room for adjustments and innovation. Moreover, the structure of the framework intends to minimize shielding behaviours by providing a process-based approach in the communication of performance requirements. In order to achieve its goal, the thesis formulates one Main Research Question with three Sub Research Question to help build its line of reasoning. The following list presents these questions to the reader.

The city of Amsterdam is following the ambitions of the National Government to operate a fully circular economy in 2050. To do so, circular urban area development (UAD) must become standard. As a start, Buiksloterham is declared as a circular urban area development project by over twenty participating parties including the municipality of Amsterdam. This master thesis aims to give recommendations about upscaling circularity in UAD. The research question that is answered is: How can the municipality of Amsterdam scale up circular urban area development by learning from projects with high circular ambitions in Buiksloterham? The answers to this question take two main issues into account. A practical issue on the implementation and possibilities for circularity and a management issue for the municipality on how they should operate in projects with high circular ambitions. The practical issue is in this research substantiated with a literature study in circular strategies for urban area development. A framework of circular strategies is realised, to indicate, structure, and reflect upon circularity in the built environment. A case study in the urban area development Buiksloterham answers the question for the municipality. Upscaling circularity in UAD requires a combination of good policy and management from the municipality. Key elements are: provide clear image and information of the plans. Explain the different roles of the municipality. Learn from the implemented circular strategies and aim for implementing the strategies on a larger scale. Upscaling requires attention to the barriers experienced by the developers. Involve the developers in both the development of the public space as with the new developers, because they have intrinsic motivation, professional knowledge and much experience.

This research investigates how to break through intra-organizational data silos in multinational engineering companies by analyzing data sharing networks. Data occurs in many ways like numbers, statistics, and documents in structured and unstructured forms. Companies consider data as one of their most valuable assets for decision-making and to increase performance. Still, often they do not see the direct results of their data-driven investments back into the organization. The volume of generated data increases so rapidly that it exceeds our capabilities if not managed well, leading to organizational data silos. Engineering companies have to deal with unique and complex projects, temporary teams, fragmented departments, and lots of unstructured data. Multicultural teams that work from dispersed locations increase the probability of miscommunication and misinterpretation of project data. Data sharing between employees of three selected case projects within one multinational portfolio have been analyzed. First, the quantitative social network analysis in Python programming exposed the structures of and the node types in the data-sharing networks. Secondly, supported by the extensive literature review, qualitative in-depth interviews identified enabling and limiting factors that determine intra-organizational data sharing in the project life cycle. It was found that balanced networks contribute the most to the exploration and exploitation of intra-organizational data. Also, the multinational context is not acknowledged to limit data sharing, but weaker links do exist between geographically dispersed teams. Measures to create and maintain balanced data sharing networks are suggested on organizational, portfolio, and project level. Future research can focus on network dynamics over time, the effect of data sharing on project success criteria, and the effect of cultural dimensions on data sharing behavior.

One of the many challenges in infrastructure management lies in managing built assets. Managing means repairing, rehabilitating and replacing assets to ensure they are able to safely fulfill their functions. To manage infrastructure assets, detailed information about the condition of all components of the asset is required to make substantiated decisions. Assets are composed of several elements and components. Individual component condition reports represent the condition found during visual inspection. The challenge for infrastructure asset managers is how to convert data about component inspections into useful information which are aggregated to make sounds decisions on the maintenance of assets in systems. Useful data that provides information about the condition of assets in systems, which are used to support budget allocation and to prioritize maintenance, is scarce. Information may be lacking, may be incomplete, may be unorganized or may need to be deciphered before it becomes useful in decision making. Furthermore, this data would be unhelpful statistics if one does not know how to apply this information to identify problems and create solutions. At a system level, infrastructure managers need to prioritize maintenance and allocate scarce resources.

2020 is a strange and disruptive year. The pandemic virus COVID-19 controls people’s lives. It influences the way we live, love, and work. Offices are empty while people work from home. When, and if people are going to work in an office again like they were used to, is the question. The events of 2020 are an extra showcase that the way we use offices is subject to change. Therefore, offices should be designed in a way that they are adaptable, reusable, and can respond to changing needs. Circular design can help to make our offices future-proof. However, since the circular economy gained attention in the office building sector, only limited progress has been accomplished. A problem within the office building sector is that insight into the possibilities of circular design is lacking. Moreover, in literature there is no circular design model specific for the building industry. Therefore, this research aims to develop a decision support tool that stimulates the communication between client and designer and provides clarity about the possibilities of circular design. This resulted in three main insights. First, a building consists of different layers with different lifespans that should be able to be refurbished, replaced, and recycled without damaging other layers. Consequently leading to an extended lifespan of the complete building and increased adaptability and reusability. Second, practical circular interventions can be categorized into four themes which are based on circular theory. Those themes are adaptability, reusability, materials, and process. Third, decisions regarding circularity should be taken early in the design process. Especially when the lifespan of the building layer is long. Understanding which possible interventions could be taken in what stage of a design process helps prioritising them and thus creating windows for circularity.

In recent years, the amount of resources consumed and the waste generated by the built environment has been growing at an alarming rate. The impacts of this are seen within our environment and felt by many. It can be said that the need to achieve circularity within the built environment is at its peak right now. Within the construction industry, the initiation and the pre-preparation phase for a circular building allow for greater flexibility for thinking and re-thinking the entire process of a circular building from the beginning to the end of life phase (re-use of components to identifying methods of disassembly). The addition of circular ambitions will escalate the trade-offs which have to be made between quality, price, sustainability and durability. Along with this the team is riled with a plethora of opportunities (re-use of components to methods of disassembly) to lead to different final outcomes, unlike a regular project where the project team can choose between well-understood options. In addition to the crucial trade-offs, the term circularity is perceived subjectively by stakeholders. Developing a consensus on the meaning of circularity and further operationalizing the ambitions can be remarked to be a daunting task. Further, the topic of circularity is still a novice in the construction industry and has the potential for high levels of innovation. To summarize, the addition of circular ambitions within the projects demands an environment of learning, exploration, ideation and experimentation. Implementation of a Stage gate or Waterfall approaches as a solution might not be an optimal solution. The lack of a commonly accepted strategy has resorted both clients and practitioners to try various methods thereby creating ambiguity regarding the process in the initiation. This could result in increasing the time spent upfront in trying to create a process for each project individually. Witnessing these problems, the research focuses on addressing the gap that there lacks a commonly accepted strategy to realize shared understanding and ambitions which are vital to incorporate circular principles within the built environment. The gap is explored within the solution space of design thinking. Within the scope of the research, a strategy is developed in which it becomes clear how the various design thinking methods available in theory can be implemented in the initiation phase. Through the developed strategy, a shared sense of understanding of the goals and ambitions will be created. Such an approach can be said to aid in realizing the circular ambitions of the commissioner. Using this strategy will also result in an exploration of other potential possibilities that are present within the project environment. Additionally, it serves as a structure that can be used by consultants for solving the client’s dilemma in the process of realizing circular ambitions. The strategy attempts at bringing order to the chaos by creating clarity within the initiation phase by prescribing design thinking attributes as a way to realize circular ambitions. The potential of this strategy lies within the initiation phase wherein extensive exploration and problem analysis through different perspectives or lenses are facilitated to achieve the highest level of circularity.

Globally the construction is a major contributor to the severity of the anthropogenic environmental impact. The sector emits 39% of the global CO2 and is responsible of 40-50% of material flows. The focus of reducing the environmental impact in buildings is, in the past, mostly attributed to the operational energy. However, due to increasing renewables and efficiency, that share is declining. Making the embodied impact in a building relatively more significant. The structure encompass the largest part of the embodied impact in buildings. The materials, components, and systems embedded in a structure are often still of high value when the building reaches its end of life, i.e. the technical service life is not yet achieved. To reduce the environmental impact of structures and therefore buildings as a whole, one should integrate design measures for new constructions to grasp the most value out of the incurred embodied impact. Three eco-effective structural design criteria are established that encapsulate the structure's whole life cycle - material environmental costs (product and construction stage), service life (use stage), and residual value (end of life and benefits beyond system boundary stage). These structural design criteria are merged from the following structural design perspectives - material selection and material use (material environmental costs); durability, maintenance, adaptability, and flexibility (service life); and waste effectiveness, disassembly, reusability, and recyclability (residual value). In the eco-effective paradigm, one focuses on the future value of a product. This may entail that more material environmental costs could be made, but in the end you will be rewared with either a longer service life or more residual value. Therefore, the emphasis is put on the latter two structural design criteria. A crucial bottleneck of not attaining the technical service life of a structure on a building level, is the functional service life. The functional service life should be equalized with the technical service life to grasp the full potential of a building structure. Three strategies have been constructed based on the structural design perspectives and the structural design criteria. Design for Durability; thus, equalizing the functional service life with maximization of the technical service life. For this strategy, it is imperative that solely one function will inhabit the building. Examples are churches, temples, museums, i.e. buildings with a sentimental and/or historical value. The second strategy is Design for Multifunctionality. This is for buildings that have proven not to stand the test of time. Therefore, conditions should be created in the structure that it could be possible for the function to be converted (n functional service life = technical service life). These two strategies are on a building level. The following strategy is on equalizing the functional and technical service life on a component level. This is done by Designing for Disassembly. In this strategy, it is known that the service life of the building relatively small. These eco-effective structural design strategies can be used by structural engineers during the conceptual design to reduce the environmental impact on the long-term.

Despite of extensive and systematic usage of ‘Lag’ type of performance metrics, Large Infrastructure Projects (LIPs) often struggle in achieving the intended performance and frequently tend to be overbudget & delivered late. This research investigates Key ‘Lead’ Indicators (KLIs) and provides suggestions on how to measure and influence them in the future large rail infrastructure projects. These ‘Lead’ Indicators are forward-looking performance metrics, unlike the ‘Lag’ indicators, and can forecast the deviation in the project performance at an early stage. Building on existing insights from theory on lead indicators, it asks: How can Key Lead Indicators be used to improve project performance of inner-city rail infrastructure projects across Europe? The research is performed through a combination of mixed qualitative research methods including literature review, case studies and an expert consultation meeting. From the literature review, it is observed that all the identified lead indicators tend towards negative aspects or events in a project. However, the research considered the indicators to be neutral which can help to forecast both positive and negative aspects of a project. The results of the literature review reveal that Design Change, Communication, Decision Making, Level of Experience, Mood, Attitude, Commitment, Conflicts, Trust, Criticism and certain External indicators are the most important and frequently repeated KLIs. Based on the literature results and three case studies each one from Sweden, Netherlands and Austria respectively, interviewees from each case are asked to respond to the questions framed in order to identify the KLIs from practice. The results of the analysis confirm that almost all KLIs observed from literature are similarly observed in practice. Level of Experience of the project personnel and Close Stakeholder Engagement are found to be the most frequently repeating KLIs across all the projects. It is concluded that in order to improve the performance of future LIPs, the identified KLIs should be responded at the earliest by measuring and influencing them. Broadly, more attention should be paid on improving the recruitment process, prioritizing client’s requirements, empowering stakeholders, improving personal relationships and creating positive project environments. A detailed set of recommendations is provided as starting points to enable the required change. This research contributes to scientific knowledge of lead indicators in project management by enriching the concepts of KLIs and discovering steps to measure and influence them. It also contributes to practical knowledge in the industry by identifying the Lead Indicators large construction projects.

Already back in 1970s, the Club of Rome concluded that the world would become unliveable for future generations, if population growth and industrialization keep up the same speed (Silvius, Schipper, & Planko, 2012). Despite this, today’s industrialization can not only be observed on land, but also increasingly in the marine environment. The “industrialization of the ocean” accelerates as sectors like offshore wind, deep water oil and gas as well as seabed mining emerge (Kronfeld-Goharani, 2018; OECD, 2016, p. 18). Therefore, more sustainable practices are needed (GPM, 2015; Hahn, Pinkse, Preuss, & Figge, 2015; Ugwu & Haupt, 2007) and the dredging industry is transforming. Next to minimizing impact, the value adding function of marine infrastructure is increasingly recognized. As the ‘productive driver[s]’ of the industry, corporate organizations, like contractors, pertain a key role to achieve such sustainable development (Hahn, Pinkse, Preuss, & Figge, 2015). Moreover, their innovative power provides the opportunity to bring about change in the industry and to leverage long-lasting competitive advantage (Kramer & Porter, 2011; Zhang, Oo, & Lim, 2018). Accordingly, to distinguish themselves during tendering and to thrive for profit maximization, conducting sustainable business becomes more and more important for contractors (R. Peenstra & Silvius, 2017, Tan et al., 2015). Responsible operations are no longer up for discussion, but are becoming central to value creation (Epstein, 2018). This results in corporate sustainability strategies (Peenstra & Silvius, 2017). The problem addressed by this study is the gap between strategy making and integration of sustainability on project level for contracting organizations. At present integrated approaches for sustainability implementation into practice are lacking (Epstein, 2018) and there is no systemic approach, how sustainability can be successfully integrated into projects (Sabini et al., 2019). Although most papers, studying sustainability in projects, provide managerial implications, their highly contextual conclusions can hardly be applied to other projects (Sabini et al., 2019). Therefore, sustainability integration remains fragmented and strongly correlates with the assigned project manager in charge of the project (van Walt Meijer, 2018; Wolfgang, 2017). Based on case study research, the study provides a success factor model entailing seven critical factors for success for pro-actively integrating sustainability into projects of marine contractors. For Science, this study unravels critical strains in managerial decision-making for sustainability on project level, which thus contributes to the scientific discussion thereof. For practice, the findings have the potential to go beyond highly contextual implications, though being derived from marine infrastructure context. This is because the seven critical success factors may provide guidance to other contracting organizations regarding the variables to consider to implement sustainability strategies on operational level. For science and practice, the conceptual C7 implementation approach tackles the need of an integrated systemic approach, which was claimed to be missing. It helps contractors to apply the (sub) success factors of the model in practice. The development areas (not, -or inconsistently fulfilled factors) can be derived and subsequently actions can be taken to close the gaps.

This study explores towards the positive side of project uncertainties i.e., opportunity. Opportunities occuring in such projects has the potential to enhance the project’s initial objective and could add more value to the project. However, due to lack of an effective approach for opportunity identification and several constraints prevailing in such large projects, opportunities are not being identified properly. This study investigates the concept of opportunity in infrastructure projects and crucial factors that could stimulate opportunity identification in such projects along with constraint’s study that hinders such identification process. Here, a roadmap is developed for opportunity identification consisting of a procedure for identifying opportunity during tender phase with an assessment model that could help in identifying value-creating opportunities for the project. This identified opportunities could be then used by the project team to exploit benefit for the contractor involved in execution but also to the client for whom the project will be delivered.

In 2015, the Paris Agreement was established with the aim to strengthen the global response in limiting the increase in the global average temperature. This can be achieved by, amongst other measures, lowering of CO2 emissions. The Paris Agreement was also signed by the Netherlands. Within the Netherlands, the construction sector has the largest environment impact of all sectors; accounting to 36% of the national CO2 emissions, 50% of the national material usage and 40% of the total energy consumption. Research has shown that implementing a CE in this sector may significantly lower these CO2 emissions and material usage. Despite the establishment of several national agreements aiming to accelerate the implementation of a CE in Dutch infrastructure projects, progress is slow. Several barriers are assumed to hamper this transition, while drivers may accelerate the transition towards a CE. This study aims to identify the barriers to and the drivers of the implementation of a CE in part of the Dutch construction sector; the infrastructure sector. The research question is “What are the barriers and drivers that respectively need to be overcome and enhanced in order to accelerate the implementation of a Circular Economy in Dutch infrastructure projects?”

Based on a review of the literature on barriers and drivers for the implementation of a CE in general and in the construction sector, a literature-based framework of CE barrier- and driver-categories was developed. This framework provided the basis in formulating the questions for the interviews. A total of 15 interviews were conducted with respondents from a diverse and balanced group of stakeholders in the infrastructure sector. Respondents were asked what they think are the barriers and drivers for the implementation of a CE in Dutch infrastructure projects. A total of 135 barriers and 72 drivers were identified during the interviews, which could be grouped in the categories of the literature-based framework. The most frequently mentioned barriers relate to the procurement of infrastructure projects, the aversion of risks and the higher costs of secondary or circular materials as compared to ‘virgin’ materials. The most frequently mentioned drivers often require the government to take action, and involved developing more binding legislation and regulation on the use and application of circular materials (at least to an extend) in infrastructure projects. Additionally, as the commissioner of the majority of infrastructure projects in the Netherlands, the government providing more room for circular innovations or pilot projects was mentioned as a driver.

While this study is novel in the sense that it is the first to provide an overview of the barriers and drivers for the implementation of CE in the context of infrastructure project, further search is required to determine how the identified barriers and drivers can respectively be overcome and enhanced. Additionally, further research to validate the applicability of the literature-based framework of CE barrier- and driver-categories in infrastructure projects in other countries is recommended.

'Construction Knowledge' is the requisite knowledge for effective and efficient construction and its use in project processes across project lifecycle for better constructability is 'Construction Knowledge Integration (CKI)'. Past researches show that there is limited integration of construction knowledge in preparation stages of the project since these are carried out by different project teams. Hence, limited integration of construction knowledge in the realm of 'Offshore Wind' projects is the main problem being addressed in this research and optimizing it is the primary objective. The scope of this research is limited to optimizing CKI in the engineering & management processes of foundations in OW projects as these remain a major 'Balance of Plant' component executed by the primary contractor. This research gathered its data through desk research (literature study) and case studies of three ongoing OW projects. The former was aimed at finding the key concepts related to CKI which support its optimization. Literature study confirmed the importance of CKI in early stages, integrating construction knowledge from a mix of relevant sources and practices. The case study was aimed at finding the existing regime of CKI in OW projects and the key issues which hinder CKI. Case data was mainly gathered through 12 semi structured interviews of project staff. It revealed that the current regime was highly informal, with high reliance on use of lessons learned data and limited integration of knowledge from fabrication, installation and past/ongoing projects. The key issues hindering CKI were found to be lack of standard protocol for knowledge integration activities and lack of integrated knowledge database which hindered knowledge retrieval, sharing and creation. The recommendations were devised for all issues that had a causal or correlational linkage with the two key issues, where the main outline was to formalize knowledge integration efforts and recommend an essential setting for an integrated knowledge database. These recommendations also address the missing link to essential knowledge sources in the current regime. Complementing the detailed recommendations to each specific issue, this research recommends the offshore wind sector to formalize CKI efforts using a mix of tools and practices, focus on integrating relevant sources of knowledge, specially fabrication knowledge and realize and share the importance of construction knowledge integration in projects.