This research delves into the multifaceted identity of Tunis, exploring how its rich history, cultural diversity, and urban dynamics intersect to shape its sense of place and belonging. The main research question guiding this study is: What is the relation between urban & social changes and the loss of “the Port-city Identity” in Tunis? Through a multidisciplinary approach that combines urban anthropology, cultural geography, architectural analysis, the study examines various neighborhoods and public spaces in Tunis, including Lac1, Lac2, Rades, La Goulette, and Carthage. Using fieldwork, interviews, observations, and mental maps from participants, the research uncovers layers of meaning embedded within the city's built environment and collective memory. From the bustling port of Rades to the historic ruins of Carthage, each neighbourhood offers unique insights into Tunisian identity, reflecting a blend of ancient traditions, colonial legacies, and contemporary challenges. The study also explores how Tunisians interact with public spaces, navigate historical sites, and negotiate their sense of belonging, shedding light on the complex interplay between physical landscapes and social practices. A significant finding, revealed through field research, is the endangered situation of local fishermen. The research discovered that these fishermen, who are vital to the region's maritime culture and identity, are being pushed out due to urban development. Their informal docking spots, crucial for their livelihood, are at risk of disappearing, which could lead to their displacement and the loss of an essential element of the port city's identity. The findings underscore the importance of preserving cultural heritage, fostering dialogue, and promoting inclusive urban development in Tunis. By embracing diversity and its port city heritage, Tunis has the potential to emerge as a vibrant and resilient hub of creativity, innovation, and cultural exchange. This research contributes to a deeper understanding of Tunisian identity and offers insights for policymakers, urban planners, and researchers seeking to navigate the complexities of identity and urban space in the 21st century.

Sufficient housing supply is one of the most significant issues in the Dutch housing market. The Dutch government aims to realise 15.000 dwellings a year by transforming vacant commercial real estate. However, a discrepancy can be noted between the number of buildings that developers have been willing to transform in the past decade and what the Dutch government deems feasible regarding the transformation of commercial real estate going into the future - a transformation dip. Next to that, office buildings with an energy label worse than C are not allowed to be used as office buildings anymore in 2023 unless they are renovated. This forms an interesting starting point as building owners are required to reassess the potential of the building and choose between different strategies, such as transformation, to prolong the lifespan. Thus, the goal of this thesis is to explore possibilities for bridging the gap between the number of buildings transformed annually on a national scale and the public transformation goals by applying a tool-the Conversion Meter- which aims to locate potential buildings in a city and asses their conversion potential. The Dutch city of The Hague is chosen as a case to apply this method, and the office stock with an energy label worse than C is chosen for the population. The following research question is answered during this thesis: To what extent can the number of office-to-housing conversions in the Netherlands be increased to meet the public goal of realising 15.000 dwellings through transformation a year? Buildings were selected out of an online real estate database using a set of preselected filters- office building in The Hague, with a minimum size of 3000m², not a listed monument and an energy label worse than C. 26 buildings were analysed, and it was determined that approximately 43% of the buildings analysed have a transformation potential based on the results of the Conversion Meter (9 out of 21 buildings-5 buildings discounted) and approximately 29% was deemed to have transformation potential based on the results of the Conversion Meter and the discussions with the expert panel (6 out of 21 buildings). In The Hague, more buildings could be found if smaller buildings are assessed too, as most of the buildings predicted to become economically obsolete (buildings energy label G) are smaller than 500m². Next to that, the normative approach of the Conversion Meter now discriminates against buildings in business parks due to a lack of facilities and location. However, as cities expand, some business parks have become engulfed by the city. The Binckhorst in The Hague is an example of a business park that will be transformed into a mixed-use area where buildings are found. Areas like these in cities provide great opportunities for adding more dwellings through transformation.

We have to change. We have to take a second look at our daily patterns. The construction sector is responsible for 36% of the world’s final energy use and 39% of energy and process-related carbon dioxide emission (IEA, 2019). 30% of this emission is due to building construction. Therefore, it is important to start to limit the carbon emission from construction processes. An efficient and sustainable way to limit the emissions is to develop buildings that are adaptable to any function or user, with the least effort and minor transformations to the building. Additionally, according to Manewa et al. (2016) buildings are continuously confronted with internal and external environmental changes to which they must respond. Those changes happen unpredictably and with many uncertainties. Buildings that are not able to react to those changes will be prematurely obsoleted, require extensive transformations, or need to be demolished, neither of which will result in a built environment that is sustainable (Manewa et al., 2016). Therefore, by not being able to adapt to the changing society and future demands, we are not building to last.

Even though several strategies have been developed and research has been conducted on the concept of adaptability, the transition from knowledge to implementation seems out of reach. Those studies mainly focus on the implementation of adaptability on the building level and not on the building as a “life cycle process”. Only a number of books and studies also examine the cooperation of the various parties in developing the proposed strategies. From this problem statement, the following research question is formulated: “What are the criteria for developing an adaptable building, and how can clients influence the implementation of these criteria in development projects?”. To answer this question, a literature review is conducted from which a list of adaptability criteria is developed. Additionally, the criteria are compared to existing Dutch cases through a case study with a cross-case analysis, and the roles and influences of parties involved in the development of adaptable buildings are established through interviews. The findings from the empirical research are used to develop an action plan which is validated by an expert panel. The action plan can be used by clients or other stakeholders as a guideline for developing adaptable buildings in the Netherlands. It can also be used to motivate and inspire other stakeholders or to start the discussion about the concept, and develop a more sustainable built environment.

Environmental harm is an influencing factor in policymaking, as climate pressures are frequently on the global agenda. An important tool to guide decision-making in the construction industry is the life cycle assessment (LCA) methodology, where the quantification of environmental harm is realised. In the method, an estimation of numerous environmental impact indicators can be made by assessing the various life cycles of a product, material, or process. Bio-based materials have been considered a valuable option to mitigate climate change. However, the LCA methodology appears to disregard certain characteristics of the material that could potentially improve their corresponding results. With the growth of bio-based materials, atmospheric carbon is stored as biogenic carbon and subsequently released at the end-of-life, the last life cycle phase of a material. The current methodology is unable to credit such storage, as it models all emissions through the life cycle as if they occurred at the same time. This research aims to explore the various options to comprehend, assess, and credit the storage of biogenic carbon. First, the different approaches to assess the storage of biogenic carbon, that are described in the literature, are assessed. Second, various methods to credit the timing of emissions in the LCA methodology will be elaborated upon. Third, the different currently active European standards are described. For biogenic carbon assessment, three methods were described: the 0/0 method, the -1/1 method, and the dynamic method. Here it was concluded that, respectively, complexity and accuracy increased, making practical implementation difficult but potentially valuable. Especially, the dynamic approach is shown to be a promising tool to accurately assess temporalities within the life cycle of a product. For possible crediting mechanisms, three methods were discussed: the Moura-Costa, Lashof, and ILCD crediting methods. Each method was based on specific assumptions, which resulted in varying credit strengths. In general, each crediting mechanism answered the demand for crediting delayed emissions, but to decide whether one of the methods is better suited than the other, further research is necessary. It is found that the organisational complexity of standardisation within the European Union influences possible alterations in the LCA. However, the research can conclude that the methodology is currently unable to capture the benefits of biogenic carbon storage, and by looking into potential crediting mechanisms, this limitation can be answered. Depending on the demand of our climate and, therefore, of policymakers, possible crediting mechanisms for the storage of biogenic carbon can be considered to be implemented through the LCA methodology.

Contemporary urban area development is a complex and multifaceted task, requiring the integration of diverse actors, interdisciplinary knowledge, and financial resources. Collaborative governance approaches have emerged as a response to these challenges, emphasizing knowledge-based collaborations and consensus-oriented decision-making. This study aims to investigate how public and private actors in collaborative governance steer on feasibility in the context of urban area development. The research focuses on understanding the assessment of feasibility, important milestones in the governance process, risks that substantially pressure feasibility, and how these risks are managed within collaborative governance agreements. The main research question is: How do public and private actors in collaborative governance steer on feasibility in the context of urban area development? The theoretical framework highlights the role of collaborative governance in steering towards feasibility and managing risks in urban area development. The empirical research, based on a case study of the Vroondaal project in The Hague, examines the assessment of feasibility and the management of risks. The findings reveal key risk factors, such as revenue increase, cost increase, cost of land development, interest rate fluctuations, land price, land sale, and market decline. Risk-management strategies include financial models, financing and interest rate considerations, land sale rate and real estate development strategies, investment and revenue adjustments, and collaboration agreements and responsibilities. The study concludes that public and private actors steer on feasibility through collaborative governance processes, as stakeholders collectively identify, analyze, and manage risks in the context of urban area development.

The construction industry has a significant environmental impact, consumes a large amount of scarce resources, generates a lot of waste, and causes a lot of emissions such as CO2 which contribute to global warming and are all reasons of great concern. A significant portion of these negative environmental impacts are caused by the building sector and attendant linear construction process. Developments with biobased materials as a circular strategy help encounter this. However, this implementation is still lacking in the building industry and the linear to a circular economy transition is still in the early stages. Moreover, real estate developers are struggling to make their business cases for circular projects financially feasible, as costs are a significant barrier. To research and understand how current circular biobased business cases are adapted and if they are future proof or use temporary measures, the following main research question is used: How are business cases adapted in order to create financially feasible and circular biobased housing developments? To answer this question, a literature study, case studies and interviews are done with the aim to gain insights into current complications and possible solutions in the business case of biobased housing developments. As well as gather perspectives from identified stakeholders & experts on these or alternative opportunities to help and speed up the transition to biobased houses. Results show that the business cases were not drastically adapted to fit the circular strategy, but temporary emergency measures were found to help realise the projects. These were: less profit for the parties involved, investors paying extra and for construction stored carbon credits, lower land price or more focus on sustainability and less on price by municipalities, subsidies, and building only partly with biobased materials and partly with e.g. concrete and bricks. It can be concluded that the traditional business case is not fitted for biobased construction as a circular economy strategy, which also contributes to why the wider necessary shift to such strategies stays out. But also that developers and other parties are willing and working on limiting the environmental impact of the building industry.

The construction industry imposes significant pressure on the natural environment, making it essential to transition to the circular economy. A step towards this goal is the adaptive reuse of existing buildings, more specifically, heritage buildings. Adaptive reuse of heritage is a difficult procedure that seeks to maintain the qualities of historic structures while modifying them for usage in the present and the future.
The aim of this research is to identify what circular economy strategies are implemented in de adaptive reuse of heritage buildings, find out what barriers still exist, and how these can potentially be mitigated. This in order to help the transition towards the circular economy.
To achieve this, literature review will provide a better understanding of the terms circularity and adaptive reuse within the context of the built environment and heritage, the literature study will also offer the potential barriers for circular heritage renovation. Case studies will explore what strategies are already implemented in adaptive reuse of heritage buildings, and barriers are experienced in the process. Finally a focus group discussion will be conducted in order to find out how these practical barriers can be mitigated in order to move towards the circular economy.
The findings reveal that there is a gap between the strategies implemented in projects and the comprehensive understanding of circular economy . The majority of implemented strategies are related to sustainability, such as reusing and using circular building materials. Barriers to implementation include ambiguities, financial constraints, lack of experience, routine practices, rules and certification, as well as a lack of urgency and social acceptance. To address these challenges, the Circular Economy Strategies for Adaptive Reuse (CESAR) model is developed as a planning and assessment tool.
Furthermore, the study provides advice for stakeholders involved in adaptive reuse projects, emphasizing the importance of collaboration, early involvement of the contractor, and integration of circular economy requirements.

Promoting sustainable travel involves encouraging train travel as a preferred mode of transportation. However, train travel in the Netherlands faces challenges with delays and slow speeds, including the planned Lelyline. This report explores an innovative high-speed train viaduct inspired by Chinese rail construction techniques as an attractive alternative to the Lelyline. By adopting modular
construction and straight alignments, this research aims to create an efficient and
visually captivating transportation solution that respects the cultural landscape. The case study focuses on a straight trajectory across the Flevopolder between Amsterdam South and Zwolle. The viaduct integrates with the landscape, enhancing biodiversity through an ecological corridor in its shadow, benefiting agriculture and the nature network. Additionally, it offers panoramic views,
recreational value, and serves as a marker of historical significance.

This research showcases the potential of a sustainable train landscape that aligns with the Dutch cultural context, providing valuable insights for future transportation projects.

Na een lange tijd waarin woningcorporaties door overheidsbeleid zijn beperkt in hun taken met betrekking tot sociale woningbouw, lijkt het belang van de woningcorporaties in het oplossen van het tekort aan middenhuur meer erkend te worden. Dit is te zien aan de recente afschaffing van de verhuurderheffing en de Nationale Prestatieafspraken met daarin inbegrepen de taak voor woningcorporaties om tot 2030 50.000 nieuwe woningen voor middenhuur te bouwen. Maar er is een overwegend tekort aan kennis over hoe woningcorporaties door middel van financiële incentives gestimuleerd kunnen worden voor het realiseren van middenhuur. Daarom wordt met dit onderzoek getracht om de kennis te vergroten over potentiele financiële incentives die woningcorporaties kunnen stimuleren voor het realiseren van middenhuur en de aspecten van de context die daarbij van belang zijn. Dit onderzoek is opgedeeld in twee fases, waarbij in de eerste fase drie potentiele incentives worden geformuleerd die vervolgens worden getest en geëvalueerd in de tweede fase. Het CMO-raamwerk staat centraal in dit proces. Eerst wordt op een bondige manier literatuur over het CMO-raamwerk en de bestaande kennis en onderzoek over middenhuur in Nederlandse context behandeld. Hieruit volgt de formulering van drie potentiele incentives en volgen verwachtingen over de bevindingen uit de interviews. Vervolgens worden de drie incentives voorgelegd door middel van semigestructureerde interviews met vijf woningcorporaties. Dit onderzoek heeft geresulteerd in CMO-overzichten van elk van de drie incentives, en die representeren wat de toegeschreven effecten van de incentives zijn, welke aspecten van context van belang zijn bij de werking van de incentives en welke potentiele consequenties kunnen voortkomen uit de implementatie van de incentives. De evaluatie van de bevindingen aan de hand van de bestaande kennis en onderzoek heeft geleid tot een beeld over in welke mate de bevindingen overeenkomen met de verwachtingen. Ook heeft het geleid tot een aantal aanbevelingen voor vervolgonderzoek. Uiteindelijk zijn er nieuwe inzichten over de incentives ontwikkeld waarbij er uitspraken worden gedaan over soort context waarin de geformuleerde incentives de corporaties beter zouden stimuleren en zullen significante elementen van een potentiele incentive worden gesuggereerd waar rekening mee gehouden kan worden bij het stimuleren van woningcorporaties.

One of the fundamental goals for the success of a construction project is found to be completion within the budget. To reach this goal, cost estimation is a key process which can be divided into the estimation of direct and indirect costs. Unlike direct costs, indirect costs are not directly connected with the performance of any particular element of a project which makes proper allocation of these costs a challenging issue. Although the classification in the ABK model (2018) provides clarity regarding the content of the indirect cost items, estimation of these costs (ABK) and especially the tasks for quantity take-off (QTO) were identified as time-consuming and lacking standardised guidelines and procedures.
At the same time, Building Information Models (BIM), which are increasingly used, offer an effective platform for linking data regarding construction costs. The fifth dimension of BIM in particular adds cost information to the 3D construction model. Full interoperability between the various information models is still a goal that has not been reached yet within the construction sector. Recent studies have examined inefficiencies caused by inadequate interoperability, like manual re-entry of data and duplication of tasks.
This research aims to positively contribute to the efficiency of the indirect cost estimation process by developing a 5D computer-based tool. The development of the tool was based on literature review and interviews with practitioners. Features of BIM applications were used and linked to the outcome of the indirect cost estimate. The tool was able to reduce manual interventions and reduce task durations, which resulted in a positive contribution to the efficiency of the indirect cost estimation process. Main benefits of the tool were hereby the structured guidelines for quantity take-offs, a reduction in manual intervention and time for QTO tasks and implementation of project changes within the outcome of the ABK estimate.

There is a growing need for social housing in the Netherlands, especially in urban areas. The construction industry faces the difficult task of quickly responding to this demand while also reducing the embodied carbon emissions of new buildings. A proposed solution to these tasks is constructing mass timber buildings, leading to cheaper buildings and faster construction times while also reducing embodied carbon emissions compared to traditional buildings (Amiri et al., 2020). Due to its high strength and low weight, research finds that mass timber is suitable for reinforced concrete replacement. In doing so, a reduction of 2,4 Million Tons of C02 Equivalent annually can be established.

However, mass timber construction faces barriers—especially when addressing social housing associations due to their strong focus on affordability and risk reduction. Since the construction of social ‘carbon neutral’ housing is a major societal and environmental challenge, this research aims to define the barriers and develop strategies for overcoming these barriers to enable mass timber construction. For this purpose, the central research question is as follows: “What are the barriers for the construction of modular mass timber social housing, and what might be strategies for overcoming them?

Since this question is explorative, a qualitative research approach is used with the double design method. In the first diamond, the barriers are discovered and defined. In the second diamond, the strategies for overcoming these barriers are developed. Expectations are that the demand for mass timber buildings is above average in urban areas where a scarcity of land occurs, and municipalities have non-statutory supplementary ambitions regarding sustainability. Therefore, this research focuses on housing associations operating in urban areas. The barriers are identified by analyzing data obtained through a series of consultations with experts and eight semi-structured interviews with social housing associations. Ten barriers resulted from these interviews, which were classified into four categories.

The first category consists of social, cultural, and organizational barriers in adopting mass timber construction. Housing associations experience unclarity about circular decisions, show risk-averse behavior, and are having difficulties changing. The second category contains sectorial barriers. These include a sectoral knowledge deficiency, strategic alliances with the traditional industry, and the unique project-based approach that forms a barrier for modular construction since it limits the degree of repeatability and standardization. The third category are technical barriers. They consist of the perception among housing associations that modular construction results in uniformity, which is further obstructed by different programs of requirements.

The strategies for overcoming these barriers are based upon insights from an online expert panel meeting. The panel consisted of two representatives of mass timber construction companies, an architect, and an expert on bio-based construction materials. There was consensus among the experts about four strategies, of which the most important is to change the conditions for mass timber. This can be done with long- and short-term knowledge increase. Other strategies include the role of the municipalities and universities. However, to enable mass timber construction structurally, the construction costs must be lowered. The industrialization of modular construction could do so. Another way is letting social housing associations review their decision-making process from cost-based to value- based. This can be done by looking at total expenditure rather than building costs. The third strategy lets suppliers create a (open) building system based on standard floorplans with the flexibility for fitting custom facades. An open building system creates the opportunity for an infill industry to arise and allows a shift from a traditional design process towards product thinking. The fourth strategy is to safeguard the future value of components by using materials with common dimensions, which contributes to a total cost of ownership approach. Changing the responsibility of a product’s maintenance incentives suppliers to use durable and remountable materials, allowing circular business models.

This research answers the central question by presenting the ten barriers and four strategies. In doing so, this research provides implications for academia by combining modularity, mass timber, and social housing. It has delivered a well-ordered list of barriers that provides implications for practice. However, the presented strategies for overcoming these barriers do not guarantee the uptake of modular mass timber construction. Since this is a relatively new topic in the Netherlands, it also requires time to be adopted and deployed in the market. A TCO approach looks most promising to enable modular mass timber construction. Future research should find how to best incorporate this within a traditional- orientated construction value chain.

Dutch real estate developers are being pressured to obtain a more sustainable corporate strategy to guarantee competitiveness and continuity of their firm. Even though this contextual pressure is being recognized by Dutch real estate developers, it is often not translated to practice. This is remarkable because studies over time have proven that sustainability has the potential lead to an enhanced competitiveness. This study aims to provide a deeper understanding of what is withholding Dutch real estate developers to implement a sustainable corporate strategy, and what the impact is of sustainable development activities is on the competitiveness of such a party. To test this, a literature study was performed to provide insight on the barriers that are present for real estate developers to become more sustainable, how the competitiveness of a Dutch real estate developer can be measured, and which alternatives Dutch real estate developers can implement to become more sustainable. A survey was distributed amongst Dutch real estate developers to determine to what extent certain barriers are withholding them from becoming more sustainable and determine the current position in regards to sustainability. The results show that Dutch real estate developers, amongst some individual barriers from other categories, are mostly being kept from becoming more sustainable due to financial barriers. This is causing Dutch real estate developers to find themselves in a reactive position towards the sustainability laws and regulations set by the government and not proactively operating to become more sustainable. By giving insight towards how sustainability can improve the competitiveness, this problem can be alleviated. Through semi-structured interviews the impact of sustainable development activities on the competitiveness of Dutch real estate developers was measured. The results in general show that sustainability does contribute to the competitiveness of Dutch real estate developers. The order of impact of the sustainable development activities that were found is (1) green product development, (2) green profiling and marketing strategy, (3) green supply chain management, (4) green human resource management, and (5) green facility management. The last phase of this research provides a preliminary design of a corporate decision tool to act as a stepping stone for further research to eventually allow Dutch real estate developers to effectively prioritize between sustainable alternatives.

Like many traditional water systems, salt fields in the coastal region of Danzhou are now facing unprecedented challenges from social development and climate change. In an era of rapid urbanization and tourism development, the project aims to provide a landscape approach that balances historical preservation with the development of local public life and tourism. By exploring the potential of the landscape narrative, the project uses landscape elements such as heritage structure, local material, local plants, buildings and roads to make salt heritage, a valuable cultural heritage, a driving force for the development of traditional salt villages. When the historic, economic and ecological value of salt fields is revalued, these traditional water systems can be revived and provide more opportunities for a coastal area to develop into a resilient system.

Changing consumer shopping trends in the last two decades and the impact of COVID-19 in 2020-2021, has led to more structural vacancy in supportive monofunctional retail areas. Since supportive monofunctional retail areas are less resilient on the long term compared to retail areas in city centres, integrated redevelopment of such areas is required to prevent further decay and add new value. Dutch municipalities majorly rely on market forces to stimulate redevelopment. Nevertheless, this does not result in desired outcomes. Different researches conclude that the local municipality has to fulfil a leading role in this redevelopment in order to achieve the desired outcome. This research focusses on how this leading role is defined and how the corporation between the local municipality and private property owners can be improved. Therefore, the following research question is formulated; How can the municipal leading role be defined during the redevelopment initiating phase and what improvements can be made in the decision-making process between the municipality and private property owners of retail space for the redevelopment to mixed-use areas? This research consists of a literature research and an empirical research to answer this question. The literature research provides an investigation of the initiative phase of project development, possibilities in organisational structures and the definition of decision-making. The empirical research consist of a case study considering a decaying monofunctional retail area with redevelopment in prospect. Stakeholder interviews are used as the main data source to investigate the project approach, organisational structure and decision-making process between the municipality and private property owners. The most important finding is that a key element of the municipal leading role was the proactive approach to the development of a masterplan for the case area in order to stimulate private stakeholder involvement.

With a shortage of approximately 315,000 homes, 4% of the existing stock, the Netherlands continues to face a significant and growing shortage of housing. This shortage is a result of various factors that either directly or indirectly have effect on the housing market. Of which some of the key factors are demographic developments such as population growth and changing household compositions; economic developments such as rising house prices, construction costs and income developments (affordability); political developments in regard to rising sustainability goals and changing regulations. These factors have a direct effect on all segments of the housing market, causing a shortage within all and predominantly for affordable of mid-priced rental homes with an estimated demand for 60,000 – 200,000 such homes over the next ten years. This demand or pressure on the mid-segment rental sector is a direct result of the inaccessibility to owner-occupied and social housing sector. As the house prices increase and the waitlist for social homes get longer the mid-segment housing market faces high demand and in turn pressurising both market parties and municipalities. Although there are developments within this segment and both parties are striving to ease the pressure on the market the supply of such homes is slow. Hence this research aims to increase the supply of mid-segment rental homes and contribute towards reducing the housing shortage in the Netherlands by hypothesising that improving the existing development process and policies within the mid-segment rental housing market would in turn improve the supply. Which brings us to the goal of the research to recommend measures/changes, that municipalities and market parties, could possibly make to improve the supply off mid-segment rental homes in the Netherlands. Given the regional characteristics of the housing market, this research adopts a case study method to analyse the development process and policies within different market types. Implying that the cases are market types and the phenomenon being explored, the development process of mid-segment homes. Learning from professionals in practice with the assistance of semi-structured interviews to first understand the existing process and policies, the problems encountered by them in the past and then collating recommendations from these actors to as how the process could be improved. Synthesising the information collected from the field research with theoretical findings to arrive at conclusions and in turn trying to answer the main research question: How can the development process of mid-segment rental housing, in the Netherlands, be improved to meet the rising demand in this segment of the housing market? On completing the research, through the interviews conducted it was found that the various actors along the process face challenges predominantly in the planning phase and challenges that arise from each other hence creating a rather uncertain environment to act in. Thus, reluctance in taking initiative and the shortage of mid-segment homes, although through this research an attempt was made to answer the main question by concluding that in order to improve the delivery of mid-segment homes it would essential to establish a well determined process, seek alternative land development approaches, allowing flexibility during negotiations and regulations, improving actor relationships, and developing policies that would not only regulate this segment but also stimulate market actors to develop mid-segment homes. Following these conclusions and aligning to the goal recommendations were made to the actors involved at an organisational and project level. Of the made recommendations the ones that stand out would be of municipalities supporting one another, involved actors form consortiums to share development risks, development of policies at a national level and finally establishing a trustful, transparent, certain, and supportive environment for each other.

Cost overruns in infrastructure projects has been a well-known phenomenon for almost a decade. As per the generally accepted definition, the industry has been measuring cost overruns as the cost exceedance with respect to the approved contractor’s budget. But researchers are realizing the fact that the decision-to-build is generally taken long before the ‘budgeting’, which thereby falsifies the existing definition of ‘cost overruns’. It has been henceforth also realized that projects under overruns also don’t offer the best capital value because their as-built costs exceed the costs estimated for them during the “decision-to-build” stage. As a result, such projects debar other deserving projects from getting approved by the funding authority/infrastructure ministry, which could potentially deliver more value for the same invested costs. A lot of projects which were in high overruns in the recent past shouldn’t have been approved/funded/preferred by the decision makers over others (For example: The Channel Tunnel in the UK, cost overruns = 100%, Denver intl. airport in the USA, cost overruns =200%). Consistent overruns also indicate that even with consecutive projects, the experts are not learning to improve on it as well. As a result, cost overruns in infrastructure projects have been a subject of discussion for more than 2 decades now. It has been realized that not only the estimates presented to the decision makers should be accurate, but also the total project costs post approval (at the decision to build point) should adhere (be controlled) to the approved estimate. Either of the two situations/or both would lead to cost escalations/overruns. Researchers have been demanding more exploration on the front-end cost escalations of the projects rather than on the cost overruns in the execution phases. It has been realized that the front-end phases allow for the maximum control over the as-built costs, but ironically, the industry experiences more cost escalations in the front-end phases. It has been emphazied that ex-post studies on the front-end phases of projects can bring revelations on how projects suffer front-end escalations. Limited research exists on the front-end phases of infrastructure projcts, with almost all of them based on the Nordic countries and only one on the Dutch governance setting by Nijkamp & Ubbels (1998). The limited research mostly includes the studies that have produced ‘characteristic escalation figures’ & the ‘factors/causes’ (technical, political & cognitive). All these factors except ‘technical & cognitive’ are quite external to the project teams and are difficult to research on through ex-post studies. Citing ‘political factors’ as the prime cause, most researches on the ‘solutions’ counterpart have been discussing over ‘political misrepresentation’ as the main factor/cause of front-end cost escalations. Very less researches have been done on the ‘technical & cognitive’ factors, which are more internal to the project teams and can be easily studied through the ex-post researches on the front-end phases of recently completed infrastructure projects. This thesis aimed to gather such ‘technical/control’ based factors & their data collection/analysis methods, in order steer them for controlling the total project costs from the very front-end phases itself. This thesis gathered 19 such ‘control’-based technical factors from Arcadis cost experts and considered it as the starting point. Structured-questionnaire surveys then helped to filter out the most important factors which lead to front-end cost escalations. Finally, 12 interviews from two recent Dutch projects (Schiphol Expansion : Landside works & Redevelopment of highway N270) gave insights on what approach should be taken for data collection [cross-learning (CL)/open-data gathering (OA)] & data analysis [top-down (TD)/bottom-up (BU)] methods in order to steer the ‘factors’ in the front-end phases of the projects. The thesis concluded that ‘project-control’ based technical factors are crucial as well, and can be steered. The research results gave some insights on which data collection/analysis approaches should be taken for steering each of such ‘factor’ from the front-end phases itself. The thesis conclusively highlighted the need of further research on gathering more such ‘factors’ and obtaining suitable data collection (CL/OA) & data analysis (TD/BU) methods for steering them. The need to focus on ‘project controls’ based factors (and not just political factors) from the very front-end phases was also conveyed.

Rapid change is quintessentially ingrained within the make-up of a city such as New York; owing to the continuous state of its evolution, buildings are becoming increasingly short-term ventures, surpassed by the latest trends and the progression of the markets. Lincoln Flex is a reactionary Multi-functional Complex, located at the juxtaposition between the recent Hudson Yards developments and historic industrial garment district, the project aims to provide the link between tall technological skyscrapers and the urban fabric of Manhattan. In this proposal, flexibility, and the use thereof, is a key defining factor and for that reason, many design principles were re-investigated in order to determine what true flexibility is and the implications that can arise from it. This has been achieved through combining both varying users and functions, enabling the complex to evolve over time, rather than becoming another individual short-term faceless entity, which stands alone unable to adapt to change and is eventually lost to time. The project builds upon current trends of quick turnaround flexible offices and residential working spaces, combined with the growing need for community and public space.

The focus in Northeast Midtown on a highly lucrative and luxurious housing market resulted in a severe shortage of affordable apartments. This project shows that it is possible to develop affordable housing in Manhattan. Increased apartment density, combined with new amenities, provides the neighborhood with spaces to live, work, teach, and relax. Creating a modern, more balanced social situation.

Many countries have committed themselves to the target for a circular economy (CE) in 2050. In this transition, the construction sector is important. One of the tools governments can use to stimulate circular building, is by incorporating circular tender criteria in land tendering. This thesis aims to improve circular land tendering requests by giving an insight in municipal land tendering goals and the translation of these goals in tender proposals. The current state of circularity in land tendering is studied by a case study of four cases. Subsequently, the findings from these cases are verified and refined in interviews with expert in the field of circular land tendering. This leads to two sets of recommendations: a land tender process and tender criteria. The circular land tendering process consists of six steps: - CE tender policy, where the available policy regarding circular land tendering must be studies - Context, where the context must be studied - Project goals, where three or four project goals must be defined, which are pursued in the tender. To stimulate circularity, this must be one of the core aims. - Tender procedure, where the best procedure is selected, which must incorporate a dialogue - Tender criteria, where tender goals are translated into awarding criteria, either quantitative or qualitative. - Awarding & control: Where the contract is drawn up and enforced. The step of tender criteria has been further explored, where criteria for circular material use and adaptive building are designed.

The goal of this thesis is to create a decision-making framework for the structural material choice for high rise buildings (between 70 m and 250 m) in the Netherlands. The main research question is: How is the structural material for a high rise building in the Netherlands chosen and how can this process become structured? Currently of the buildings in the Netherlands above 120 m, 86% have only reinforced concrete as structural material. This raises the question if the preference in the Netherlands for concrete comes from a clear decision-making process or if it originates elsewhere? In theory this decision-making process follows an organized cycle called the Basic design cycle. In practice preferences based on experience gained from former projects play a role, which results in deviation from the theoretical decision-making process. By gaining insight in the differences between theory and practice in the decision-making process, this thesis tries to identify the main differences arising in the structural material choice process. Four differences between theory and practice – regarding the structural material choice process of high rise buildings in the Netherlands – have been identified. By conducting interviews, these differences between theory and practice have been further researched and confirmed. (1) Disproportionately less steel is used for the main load-bearing structure of high rise buildings in the Netherlands. (2) Reasoning behind design decisions is often not made clear. (3) Building methods of contractors influence the structural material choice. (4) Arguments and expectation don’t match reality. For example, figures based on the construction time of the buildings in the Netherlands above 120 m show that prefab concrete buildings don’t always have a shorter construction time than cast in-situ concrete. In this thesis Difference 2 and 3 are combined and addressed together by creating an advisory excel-tool. The goal of this excel-tool is to give the structural engineer – early in the design process of a high rise project – insight in the influence of the structural typology on: cost (direct and indirect costs) and sustainability (environmental cost). Early in the design process very little details are available about the design of the high rise building and a lot of things can still change. Because of that, the input of the tool is kept simple: the height of the high rise building. As output a top ten of structural combinations is given. The structural combinations are a combinations of (1) stability system, (2) structural material and (3) floor type. This top ten is determined by calculating the (direct and indirect) costs and the environmental cost (sustainability) of twenty-six different structural combinations at all heights within the height range of that stability system. Eventually the top ten shows which out of the twenty-six structural combinations have the lowest (direct and indirect) costs and the lowest environmental cost (sustainability). This way a structural engineer can explore early in the design process what the influence of his or her design choices are on the final result and take the top ten structural combinations into consideration.