452 research outputs found
Sort by
Ruimtelijke transformaties van de steden in het Randstadgebied (12de-20ste eeuw): Een vergelijkende analyse van de stadsplattegronden
Get PDFIn this study, the transformation of the form of nine cities in the Randstad between 1250 and 1940 in relation to changes in infrastructure is central, namely Utrecht, Dordrecht, Leiden, Haarlem, Delft, Gouda, Amsterdam, Rotterdam and The Hague. Within this time span three periods of great spatial dynamics are identified, namely the period 1240-1450, 1580-1680 and 1870-1940.
From the eleventh century large areas of hitherto inaccessible peatland were reclaimed and made suitable for agriculture and habitation, creating a number of peatland streams. Water became the main vehicle for goods transport. Along the peat streams, small settlements were formed, part of which developed as market centers for the environment. After the establishment of a system of continuous shipping links through the Randstad area in the thirteenth century, Central Holland became an alternative to the goods transport between the trading centers of the moment, namely the German Rhineland, Flanders and the Baltic Sea. Central Holland performed a role as a transit between the trading chains. Some cities transformed from a pre-urban to an urban settlement. The interlocal infrastructure formed the main structure of the cities. In a second phase of urbanization around 1350, cities developed into industrial centers. In this study, this development is referred to as the term spatial maturity. Typical for this period is that at the intersection of long-distance (water) ways an urban center developed with a port and public buildings. The street pattern was oriented on this center. The cities showed a remarkable resemblance to size and spatial thematic. Location for economic functions was found in particular by using existing structures. Harbors were made in inland waterways, markets were held on quays, bridges and streets. The main spatial themes in this period are: the development of ports, the development of the street pattern, the extensions and the emergence of an urban center with public functions.
In the sixteenth and seventeenth century, the goods transport through Holland grew, and Amsterdam expanded to the centre of world trade. The infrastructural network barely changed during this period. The various urban maps in this phase show a great diversity. Some of the cities were performing in the superregional goods transport and showed a great spatial dynamics. In Amsterdam and to a lesser extent Rotterdam the cities expanded towards the IJ and the Meuse with ports and industrial areas. Leiden applied to the textile industry. In the city there was strong densification and expansion with neighborhoods for the textile industry. The Hague grew in particular as a government center of the Republic. The other cities felt less dynamic. Extensions hardly took place, and in the cities mainly marketplaces were created. During this period, space for economic functions was created. Inland ports were constructed at the edges of the city and marketplaces were made. Important spatial themes in this period are the construction of ports and marketplaces and the strengthening of the urban center. Typical for the city maps during this period was the strengthening of the urban center in addition to the relocation of overseas and regional market functions to the city's borders. There was a specialization in the city maps.
Comparing the city maps with each other, they made a development from uniformity to diversification to leveling between 1250 and 1940. Typical for the spatial development was that in the first period an urban centers was created in which the various urban functions were concentrated. In the second period, specialization took place, in addition to strengthening the regional market function in the late medieval centers, functions were moved to the city edges. In the third period, the international goods transports continued to be moved out of the late medieval centers. In addition, the routes between the central station and the centers were a centers shopping area, passenger flows determined the spatial configuration
Imagine: Energy
No full textClimate design and climate engineering are nowadays standard in the design process. The more successful we are in this, the less energy we need to run the building during its useful life and we can focus instead on an additional aspect: the embodied energy — the energy we need for the material production and construction process. Interestingly, the reduction in energy used in a climate-efficient building during its lifetime is equal to the energy consumption necessary to produce and install the building. This aspect triggers us to reconsider the design potentials of focusing on less energy in the construction. Which materials make sense energy-wise? Do we need to build with simple materials for 500 years or should we go high-tech and design the complete life cycle for a perfect reuse with maximum recyclable materials? Or should we build out of materials that can be used as energy after being a building? This publication focuses on the embodied energy aspects of building materials, their life cycle and their potentials for reuse as energy or in construction, and presents some far-reaching design ideas
Performance Assessment Strategies: A computational framework for conceptual design of large roofs
Get PDFUsing engineering performance evaluations to explore design alternatives during the conceptual phase of architectural design helps to understand the relationships between form and performance; and is crucial for developing well-performing final designs. Computer aided conceptual design has the potential to aid the design team in discovering and highlighting these relationships; especially by means of procedural and parametric geometry to support the generation of geometric design, and building performance simulation tools to support performance assessments. However, current tools and methods for computer aided conceptual design in architecture do not explicitly reveal nor allow for backtracking the relationships between performance and geometry of the design. They currently support post-engineering, rather than the early design decisions and the design exploration process.
Focusing on large roofs, this research aims at developing a computational design approach to support designers in performance driven explorations. The approach is meant to facilitate the multidisciplinary integration and the learning process of the designer; and not to constrain the process in precompiled procedures or in hard engineering formulations, nor to automatize it by delegating the design creativity to computational procedures. PAS (Performance Assessment Strategies) as a method is the main output of the research. It consists of a framework including guidelines and an extensible library of procedures for parametric modelling. It is structured on three parts.
Pre-PAS provides guidelines for a design strategy-definition, toward the parameterization process. Model-PAS provides guidelines, procedures and scripts for building the parametric models. Explore-PAS supports the solutions-assessment based on numeric evaluations and performance simulations, until the identification of a suitable design solution. PAS has been developed based on action research. Several case studies have focused on each step of PAS and on their interrelationships.
The relations between the knowledge available in pre-PAS and the challenges of the solution space exploration in explore-PAS have been highlighted. In order to facilitate the explore-PAS phase in case of large solution spaces, the support of genetic algorithms has been investigated and the exiting method ParaGen has been further implemented. Final case studies have focused on the potentials of ParaGen to identify well performing solutions; to extract knowledge during explore-PAS; and to allow interventions of the designer as an alternative to generations driven solely by coded criteria.
Both the use of PAS and its recommended future developments are addressed in the thesis
ICT-related transformations in Latin American metropolises
Get PDFThe use and application of ICT within and between cities is resulting in significant urban transformations, making cities more connected as well as more complex. A sub-discipline of urban studies - urban ICT studies - has recently emerged to explore, analyse and theorise how the technological advances are transforming urban forms, urban processes and the perceptions of urban life. ICT-related transformations in cities of the developing world, however, have not received enough academic attention until now. This book makes a contribution to the field of urban ICT studies in cities of the South, by exploring the ICT-related transformations in the Latin American urban scene. Based on Gabriel Dupuy’s notion of ‘urbanism of networks’, this explorative research identifies and analyses the recent transformations at three levels: the ICT infrastructure networks, the networks of production and consumption of ICTs in the local urban economy, and the diffusion of digital connectivity in everyday life. The book also presents the situation of digital connectivity in Buenos Aires and Lima, selected as case-studies because singular ICT-related processes are occurring in these two large metropolises. Besides from identifying the urban main trends at the different levels, the results have been also useful to spell out the main trends regarding urban functioning and the urban form, as well as the new problems and new opportunities that the introduction and development of ICTs bring to Latin American cities. The main findings point out that Latin American metropolises have great assets at the infrastructural level as main nodes of the ICT backbones infrastructures. However, there is a profound contradiction between the ICT-related developments occurring in the urban economies, and the social and cultural life of the cities. The low performance of the Latin American metropolises regarding their integration in the global economy and the production of science and technology are in stark contrast with the eagerness of Latin Americans to be connected and to be able to participate as citizens in the network society. These contradiction constitute the largest problem of the future of the metropolises
Level of detail in 3D city models
Get PDFThe concept of level of detail (LOD) describes the content of 3D city models, and it plays an essential role during their life cycle. On the one hand it comes akin to the concepts of scale in cartography and LOD in computer graphics, on the other hand, it is a standalone concept that requires attention. LOD influences tendering and acquisition, and it has a hand in storage, maintenance, and application aspects. However, it has not been significantly researched, and this PhD thesis fills this void.
This thesis reviews dozens of current LOD standards, revealing that most practitioners consider the LOD to be comprised solely of the geometric detail of data and there are disparate views on the concept as a whole. However, the research suggests that the LOD encompasses additional metrics, such as semantics and texture. The thesis formalises the concept, enabling integration and comparison of current LOD standards. The established framework may be applied to cartography and different forms of 3D geo-information such as point clouds.
Following the formalised concept, a new LOD specification is presented improving the LOD concept in the current OGC CityGML 2.0 standard, a prominent norm in the 3D GIS industry. The specification introduces 16 LODs for buildings that are shaped after analysing the capabilities of acquisition techniques and a large number of real-world data sets. The improved LOD specification may be integrated with product portfolios and tenders, preventing misunderstandings between stakeholders, and as a better language for communicating the specifics of a data set to be acquired.
The specification also considers different approaches to realise the data. Such geometric references result in dozens of different variants of the same LOD. 3D data according to the LOD specification was generated using a procedural modelling engine that was developed over the course of the research. The engine is capable of producing 3D city models in a large number of different variants and according to the CityGML standard.
The thesis also catalogues the many different ways to create 3D city models. A prominent technique for producing data in a different LOD is a generalisation, i.e. simplifying a 3D city model. The inverse–augmenting the LOD of a dataset–has not been researched to a great extent, and this thesis gives an overview of the topic.
This research demonstrates that it is possible to generate 3D city models without elevation measurements, inherently augmenting the LOD of coarser data (2D foot-prints). The method relies on machine learning: several attributes found in 2D data sets may hint at the height of a building, thus enabling extrusion and creating 3D city models suited for several applications.
Some acquisition techniques may result in multi-LOD datasets, and nowadays there are some regions represented in different, independent data sets. However, it was found that possibilities to link such data are deficient. The lack of linking mechanisms inhibits acquisition, storage, and maintenance of multi-LOD data. Two methods for linking features across two or more LODs have been developed resulting in an increased consistency of multi-LOD datasets. The first method links matching geometries across multiple LODs, while the second method establishes a 4D data structure in which the LOD is modelled as the fourth (spatial) dimension.
It is often believed that the more detailed 3D data the better. However, similarly as in computer graphics, dealing with data at fine LODs comes at a cost: such datasets are harder to obtain, their storage footprint is large, and their usage within a spatial analysis may be slow. Scarce research has been dedicated to investigating whether an increase in the LOD of the data brings a comparably significant increase in benefits when the data is used in a spatial analysis.
First, an analysis using real-world multi-LOD data was carried out. Different LODs of spatial data covering the Netherlands was used in a spatial analysis to refine population maps, obtaining different results for each LOD. However, several problems are exposed, revealing that using real data for such investigations is not optimal.
The remainder of the research focuses on using procedurally generated data for such experiments. Synthetic data in several different LODs has been generated and employed for four spatial analyses (estimation of the building shadow, envelope area, volume, and solar irradiation). The experiments result in different conclusions. Finer LODs usually bring some improvement to the quality of the spatial analysis, but not always and such may be negligible. The results of the experiments ultimately depend on the spatial analysis that is considered. The varying results between different spatial analyses make each of them unique. Furthermore, the benefit a finer LOD brings to a spatial analysis is not always clear and easily measurable. In short, striving to produce data at finer LODs may please the eye, but this is not always counter-balanced in the benefit it brings to spatial analysis.
A further addition to the equation above is that when realised, 3D city models are unavoidably burdened with acquisition errors. An error propagation analysis was performed by disturbing the procedurally generated datasets with a range of simulated positional errors. Comparisons have been made between the intentionally degraded datasets and their error-free counterparts, thus obtaining the magnitude of uncertainty the positional errors cause in spatial analysis. Based on these experiments, several findings are discovered, most importantly:
How the LODs are realised (which geometric references are used) has a larger influence than the LOD. A coarse LOD produced with a favourable geometric reference may yield better results than a finer LOD realised with an unfavourable reference.
Positional errors considerably affect spatial analyses. The effect is comparable across similar LODs. Simpler LODs are slightly less affected by positional errors, but they may contain a large systematic error.
Errors induced in the acquisition process generally cancel out the improvement provided by finer LODs. The main conclusion is that in the considered spatial analyses the positional error has a significantly higher impact than the LOD. As a consequence, it is suggested that it is pointless to acquire geoinformation at a fine LOD if the acquisition method is not accurate, and instead, it is advised to focus on the improvement of accuracy of the data.
The thesis proposes additional research for future work. For example, since this research focuses specifically on 3D building models, it would be worth extending the research to other urban features such as roads and vegetation. Furthermore, quality control in 3D GIS does not encompass the evaluation of the LOD of data. Hence integration of the LOD in quality standards should be a priority for future work
Networks and Fault Lines: Understanding the role of housing associations in neighbourhood regeneration: a network governance perspective
Get PDFThis study aims to increase our understanding of the role of social housing organisations in neighbourhood regeneration governance networks, in order to enhance the performance and outcomes of these networks. Our understanding of how governance networks work is still limited, especially concerning the role of non-state actors like housing associations. Hierarchical government steering is increasingly mixed with market mechanisms and networked forms of decision-making. These shifts in governance often result in more complex decision-making that can easily lead to deadlocks, low-quality outcomes and ambiguous anchorage of democratic principles.
Neighbourhood regeneration takes place in rather exceptional governance networks. The organisations involved, and the problems at hand, are place-based. Actors, like housing associations, local authorities and community organisations, are more or less ‘locked’ into the regeneration network and need to collaborate in order to solve the problems. The complexity of neighbourhood renewal processes is often very high, due to the large number of actors involved, and the combination of insufficient housing quality, lack of affordability and supply, along with social and economic problems that need to be addressed.
Housing associations focus on the delivery of affordable decent quality housing; but, in many countries–like the Netherlands and England–these organisations also have an important role in neighbourhood regeneration. Housing associations are non-profit organisations that provide housing for low and moderate-income households. They operate largely autonomously from the government, although they are often strongly regulated and dependent on government subsidies. Housing associations in England and the Netherlands share many organisational characteristics and hybrid third-sector values emerging from the need to balance social and economic objectives. They have largely similar tasks and responsibilities, but work in very divergent contexts. This study devotes careful attention to the contingencies of time and place of decisionmaking in order to regenerate insights that are also relevant outside the case-study areas. Therefore, this study places Dutch and English housing associations in their respective political economies, welfare regimes and rental housing systems. The study also highlights the ambiguous position–between state, market, and society–of housing associations.
Neighbourhood regeneration evolved from slum clearance and complete area redevelopment in the 1950s and 1960s, towards more integral place-based approaches–in the 1970s and 1980s–with a stronger emphasis on improving the existing housing stock and involving local communities. The nature of the involvement of housing associations in neighbourhood regeneration has changed over time in response to government policies, public opinion, their own strategies, and the strategies of their umbrella organisations. In both England and the Netherlands, their increasingly prominent role –especially after the start of the new millennium–was driven by pressures on housing associations to take a leading role in neighbourhood regeneration.
A governance network perspective on neighbourhood regeneration
The emergence of the ‘network society’ has led to a fragmentation of power and resources. This fragmentation has led to increased interdependence of actors; public, private and community actors need to collaborate to solve problems. This study uses a governance network approach to explore the complexity and uncertainties involved in neighbourhood regeneration decision-making. The study explores five interrelated questions [see Chapter 1, §1.2], each related to a component of a theoretical framework on decision-making in a network setting. These questions involve context, networks, actors, processes and outcomes.
In order to answer the research questions, a qualitative, comparative, longitudinal exploration based on a case study methodology, was conducted. To ensure that comparable cases were explored, similar ‘focal actors’ were chosen (i.e. housing associations), as well as similar ‘policy outputs’ as starting points for the study (i.e. the drafting of neighbourhood regeneration plans). Based on these criteria, housing association Midland Heart, and the neighbourhood Lozells in North/West Birmingham, was selected as the English case study. In the Netherlands, housing association De Huismeesters, and De Hoogte, a neighbourhood in Groningen, were selected. Personal accounts have been an important data source for this study; 70 interviews with 45 different individuals were conducted between 2007 and 2014 in Groningen, and Birmingham. In addition, for the case study in The Hague (Chapter 5), around 25 interviews were conducted in 2004. That chapter was a first introduction to the explanatory capabilities of the network governance perspective.
Research results
The introductory chapter explores contextual factors–such as economic, social and political developments–that affect the role of housing associations in neighbourhood regeneration. Chapters 3 through 7 contain sections which describe the context relevant to that specific chapter. Chapter 8 is more reflective in nature and discusses the impact of post-crisis ‘Big Society’ (UK), and Participation Society (NL) government policies, as contingency factors for the role of housing associations in relation to local communities. Finally, Chapter 9 brings all the components of the theoretical framework together and especially reflects on the significant impact of contextual developments on the role played by housing associations in neighbourhood regeneration decision-making, and delivery. This research also highlighted the strong network relationships between housing associations and local authorities, but also revealed the often troublesome interactions between housing associations and residents. The title of this thesis: “Networks and Fault lines” is intended to reflect this.
This research took place in a period of unexpectedly dynamic economic, social and political developments, i.e. the global financial crisis, the housing-market downturn, government austerity, and a more restricted interpretation of the state’s role in delivering welfare services. The impacts of these developments varied across the two cases. The Dutch housing association proved more resilient to contextual developments than its English counterpart; especially its ability to continue the neighbourhood investment programme. National government funding was less important to the Dutch housing association: the organisation already had access to neighbourhood regeneration investment resources. Other contextual factors, such as the characteristics of the national political economies, welfare and housing systems, indirectly affected the role played by housing associations. These factors mainly influenced the characteristics of the governance networks and the decision-making processes within these networks.
Explored through the networks component are the characteristics of the governance networks that housing associations participate in: interdependencies, strength of network relations, and the nature of the coordination mechanisms that underline decision-making. The key concepts to exploring networks are introduced in Chapter 2, and further developed in Chapters 3, 5 and 7. We found high levels of uncertainty, generated by the variety of, and the interdependencies between, actors, the closed-mindedness of actors to the arguments of other parties, and the changes in composition of the governance network. For example, the research found substantial cross-national differences, and indications that network characteristics change and fluctuate over time. In contrast to the situation in Groningen, the dependency of the Birmingham network on external government funding negatively affected the stability and the performance of that network. In Groningen, top-down government intervention also negatively affected the stability of the network, but for other reasons. The, short-lived, abundance of resources for regeneration led to such a high number of new actors, issues, goals and decision-making arenas that the governance network was unable to function properly for some time. The network actors increased the complexity of policy games of their own volition. Sometimes, this was induced by the national government, when local network actors responded to steering instruments such as government subsidies. This led to more network complexity and dynamics in the form of new goals, network actors and decision-making arenas.
The third research component–the actors– explored the perceptions and objectives of housing associations, and other key network actors concerning neighbourhood regeneration investments and activities. Housing associations in both case-study areas took a prominent role in neighbourhood regeneration activities, and collaborated closely with local authority departments in drafting regeneration plans. The housing associations regarded improving the quality and variety of the local housing stock as an important element in creating a more mixed community, and retaining and attracting more affluent households. The local authorities supported this predominantly longterm ambition. Residents were more concerned with tackling short-term liveability issues, such as anti-social behaviour, crime and litter.
The role of housing associations changed during the 2007-2014 fieldwork period. From occupying a leading role in the regeneration process–in partnership with the local authority–at the start of the exploration in 2007, this role transformed into a more facilitating and supporting role. This appears to have been brought about by two related factors: a serious decline in available regeneration resources, and an increased emphasis on the responsibilities of individual residents and local communities under the influence of the Participation Society agenda, in the Netherlands, and the Localism agenda in England.
Residents and private-sector organisations were rarely directly involved in regeneration decision-making. With a little hindsight, one could formulate the contention that these actors were not fully represented in the governance network because the incumbent network actors (i.e. the housing associations and local authorities) chose the devil they knew. They opted for state involvement to acquire investment resources, rather than facing the uncertainties that would have resulted from expanding the network to include residents and private-sector organisations as full and mature network actors. Decision-making processes constitute the fourth component of this study. It explored the decision-making interactions inside the neighbourhood regeneration networks, with a special focus on the interaction strategies used by housing associations. This study found that housing associations in the Groningen and Birmingham cases had a prominent and often leading role in the policy arenas where regeneration policies were developed. National governments in both countries had a strong impact on how these processes evolved, leveraged by the alluring investment resources offered by national regeneration programmes, and the preconditions accompanying these resources. Decision-making took place in arenas that almost exclusively consisted of housing association and local authority professionals. Residents were largely given a consumerist role in the process: their views on neighbourhood needs were collected through various instruments to involve residents, such as surveys and street interviews.
Their views were, implicitly, taken into account in the decision-making. Residents were most often not part of these processes and not involved in the development of regeneration investments plans. Not all decision-making arenas were closed to residents. The housing associations in both case-study areas did involve residents as co-decision-makers in more ‘hands-on’ neighbourhood issues such as improving playareas, tackling garbage and litter problems.
Decision-making conflicts and deadlocks were rather limited in the investigated governance networks. There was a strong impetus for the housing associations and the local authorities to reach agreements: no consensus would very likely mean no national government funding. Housing associations and local authorities used rather traditional instruments to facilitate decision-making, such as limiting the number of actors involved, and enforcing strict time constraints on decision-making processes.
Outcomes are the fifth and last component of this study. In this component we explored how the network–and housing associations in particular–contributed to decision-making and neighbourhood regeneration outcomes. It is evident that the housing associations in the case-study areas contributed significantly to neighbourhood regeneration activities, not only because they channelled considerable investments into the areas, but also due to their strong network relations and frequent interactions with government agencies and local communities. The actions of network actors have improved the quality of some parts of the housing stock. Joint projects have been delivered to improve the public realm and contribute to neighbourhood safety.
The research found that actors used very divergent process, input, output and outcome yardsticks to measure success, ranging from the number of projects and activities started, to the amount of money spent, the increase in resident satisfaction, the number of decision-making conflicts overcome, and the improvement achieved in quality-of-life indicators. These yardsticks changed over time and varied from actor to actor. This demonstrated how fluid the assessment of regeneration outcomes can be. New rounds of decision-making, as well as new network actors, led to a review of old decisions, sometimes with a different assessment of the outcomes achieved.
Challenges for governance network approaches
The governance network perspective has supported the exploration of the role played by housing associations in neighbourhood regeneration decision-making. It has increased our understanding of the complexity and the uncertainties involved in networked forms of decision-making. Governance network theory helped us identify instruments and strategies used by housing associations and local authorities to support regeneration decision-making. The governance network perspective is a rather new academic discipline that can be further developed. This study contributed to this development by addressing some issues and challenges; firstly, the role of residents in decision-making arenas, and secondly, the assessment of governance network outcomes.
The theoretical and methodological implications of residents as neighbourhood regeneration co-producers
Policy-makers expect a more active role of residents and local communities in the co-production of neighbourhood regeneration. This more inclusive approach may contribute to the quality and legitimacy of decisions made in governance networks, but the efficiency of decision-making will most probably not benefit. The trade-off between efficiency and legitimacy that arises from increased resident involvement is a challenge that calls for the further development of the governance network theory. This research suggests several avenues that could be followed to address this challenge. Firstly, a more extensive use of Habermas’s Theory of Communicative Action, as explored in Chapter 8, might be undertaken to supplement the governance network theory.
Secondly, more use could be made of the body of knowledge and theories developed in England during the New Labour government (1997-2010), which was often explicitly concerned with networks that linked governments with citizens and local communities [see Chapter 9].
The assessment of governance network outcomes
Co-production of neighbourhood regeneration can lead to more democratic and inclusive approaches to decision-making. This is likely to result in better outcomes, but not necessarily in greater consensus among the actors involved. Within network governance approaches, there is a tendency to define satisfactory outcomes as those that enjoy the greatest joint support of the actors involved in the process. More inclusive approaches, which engage a wider range of actors, might appear to be less successful as the benchmark of satisfaction is raised to include a wider range of preferences and experiences. Therefore, we need a more refined assessment of outcomes produced by increasingly heterogeneous networks.
Governance network approaches could develop methods — or develop connections with other theories and methodologies — that help evaluate the success of governance networks by combining substantive regeneration outcomes, actor and stakeholder satisfaction, and network learning. Preventing ‘cherry picking’ in the use of assessment yardsticks is essential, given the disinclination of actors to closely scrutinise the outcomes produced by governance networks (as found in this research). Further development of network governance approaches may increase our understanding of how actors construct the yardsticks to evaluate success, and provide tools to facilitate a more comprehensive assessment of network outcomes [See chapter 9].
Housing associations as champions of networks in vulnerable neighbourhoods
This research demonstrated that housing associations can play an important stabilising and cohesion-enhancing role in neighbourhood regeneration networks. Their interests are vested in the value of the local housing stock, and this financial incentive secures some level of commitment to vulnerable neighbourhoods. Their hybrid characteristics enable housing associations to collaborate with community, market and government organisations. Moreover, their professional capabilities and their relatively-easy access to resources allow them to champion neighbourhood needs, in cases where communities lack the capacity or cohesiveness to champion their own.
Using the leeway that housing associations have, as a hybrid organisation, is an extremely delicate exercise. They should seek a balance between the very different and variable expectations of the outside world. This balancing act is only attainable when housing associations can combine proficiency in network management, with increased accountability. Each neighbourhood is different, and housing associations should take a role that is appropriate to each neighbourhood. To do this, they should increase their knowledge of the neighbourhood challenges and assess the capabilities of residents and the local community to address these problems. Housing associations can support the development of governance networks to address these problems by helping craft networks in such a way that they include all relevant parties, and by providing small but stable funding to support network development and by improving accountability in decision-making processes.
There are strong arguments for housing associations to take a central role in neighbourhood regeneration. Housing associations are among the most prominent frontline agencies supporting vulnerable people and places. Through their housing stock, they are literally ‘anchored’ in the most deprived communities. Housing associations should not become the ‘jack-of-all-trades’ in neighbourhood regeneration, but can help develop, nurture and maintain well-functioning and stable regeneration networks which vulnerable neighbourhoods need. Housing associations can be the long-haul champion that neighbourhoods and local communities need
Developing a Framework for Qualitative Evaluation of Urban Interventions in Iranian Historical Cores
Get PDFIranian historic city cores are important parts of modern cities because of their valuable monuments and morphology but are also significant because of their population density, location and the major governmental functions they house. Since 1920, modernisation policies and urban development trends in Iran have justified spatial transformation and redevelopment and the demolition and destruction of traditional urban fabrics as a way to provide contemporary requirements and hygiene improvements for the residents. As the UNESCO recommendation on the Historic Urban Landscape argues, historic urban cores can only sustain their role in the daily life of the city by getting prepared for and participating in this transformation process.
Disagreement over the value of historic urban cores on the one hand and inevitable modification of urban areas in a developing country like Iran on the other, creates a problematic condition for the preservation of the historic environment. The Valletta Principles for the Safeguarding and Management of Historic Cities, Towns and Urban Areas states that historic towns and urban areas require an integrated approach including their “protection, conservation, enhancement and management as well as their coherent development and their harmonious adaptation to contemporary life”. In order to support the process of reaching a balance between these spatial targets in Iran, this research discusses the relation between urban transformation projects and their heritage context. In doing so it connects international literature on urban quality and traditional Iranian urban forms to contemporary Iranian urban design practice.
To achieve this integration between urban heritage and spatial development, a framework of quality attributes has been developed to evaluate urban interventions in a heritage context. The three main pillars of this framework have been extracted from and inspired by international literature and guidelines. Place-making theories have proved to be especially helpful. An analysis of traditional urban forms in Iran and their main characteristics - especially for the urban type of the bazaar — has provided a list of specific and relevant parameters. The framework has been tested by evaluating two case studies in Shiraz that illustrate two different approaches to heritage intervention on an urban level. The outcome has led to modification of the framework and new research questions
Spatial Planning and High-tech Development: A comparative study of Eindhoven city-region, the Netherlands and Hsinchu City-region, Taiwan
Get PDFHigh-tech development–which lies at the very heart of the processes of economic growth–has been recognised by many developed and developing countries as a strategic instrument to enhance and sustain their competitiveness in the global economic network. Although the concept of high-tech development differs between countries, many share the underlying assumption that the core of high-tech development is to create a sound environment where innovation thrives. This ideology implies a definite spatial dimension. As a result, various spatial strategies have been formulated and implemented to support high-tech development. This has had intentional and unintentional effects on the economy, society and space.
Numerous studies have been devoted to exploring, analysing and theorising this global phenomenon. However, there has been less attention given to the role spatial planning may play in the process of high-tech development and to the factors that shape the spatial planning approaches to high-tech development in a particular place. The major objectives of this research are to advance the knowledge of the role of spatial planning in the process of high-tech development, and to establish an analytical framework that helps reveal the major institutional factors that shape spatial planning mechanisms for dealing with the spatial issues of high-tech development in different places. This contributes to the field of high-tech spatial policies transfer and lesson-drawing.
In order to explore the major factors that shape the practices of spatial planning in hightech development, a comparative approach is applied in this research. The Eindhoven city-region in the Netherlands and the Hsinchu city-region in Taiwan are selected as case study areas. Both city-regions can be recognised as success stories of high-tech development not only on a national scale but also on a global scale, despite the fact that they apply different approaches. In the Eindhoven city-region, the governments act as supporters and governors. High-tech development in the city-region is a result of close collaboration between different levels of government and other parties. In contrast, in the Hsinchu city-region the governments act as providers in high-tech development.
By critically reviewing relevant literature, the research begins with the identification of principal components of high-tech development and their spatial dimensions, and with the establishment of a set of comparative frameworks, which are built upon the concepts of institutionalism and previous comparative studies of spatial planning systems. On the basis of the frameworks, the comparative study is conducted. Four major conclusions are drawn in this research.
First, R&D capital, relational capital and human capital can be identified as the principal components of high-tech development, but the conception of the principal components is not static. It may change through time and space, and be influenced by contemporary technological development and dominant discourses about high-tech development. Additionally, how governments in a particular place conceptualise the principal components will influence the content of their strategies for high-tech development.
Second, how governments in a particular place use their spatial planning system and tools to conduct, facilitate and/or coordinate the development of high-tech spaces is influenced by the socio-political context (e.g. model of society, administration system and conceptualisation of rights in land), conceptualisation of the principal components, dominant style of spatial planning, but also by their historical roots and contemporary technological capacities. At the city-regional level, the particular culture characteristics and historical experience of a city-region also have effects on the approach to spatial governance.
Third, it is common that governments recognise the necessity of collaborating with knowledge institutes and high-tech firms in the process of high-tech spatial development, because they have access to a wide range of know-how and crucial resources. The creation of new institutional arenas to invite institutes and firms to participate in the process of decision-making is a good strategy for governments, although they must assure that the decision-making process is transparent and accountable, and meets the principles of social justice.
Finally, the two cases have shown that a successful high-tech spatial development would have spatial effects on the surrounding areas, such as traffic congestion, imbalance between land supply and demand for housing and/or industrial land, and so on. It is necessary to anticipate and monitor continuously the externalities of the development from a more comprehensive perspective and to leave room for adjustment to the spatial planning and governance approaches.
The analytical framework built upon the institutional concepts of Ostrom and Scharpf worked well in this research, but in the process of conducting the empirical study I found that the framework of institutional analysis I established for the empirical study implied a temporarily fixed situation for analysis. Such a framework did create an easier situation for analysis, but proved difficult to use to investigate and explain the dynamic interrelationships between the changing institutional contexts and the decision making of high-tech spatial planning at a specific place and time.
While considering this limitation, I adopted a diachronic approach to complement the empirical study of part three, in order to understand the influences of prior institutional developments and specific episodes on later policy/decision making and action taking. In the future, if other studies consider applying the frameworks of this research, the effect of historical path dependency has to be taken into consideration
Facade Refurbishment Toolbox: Supporting the Design of Residential Energy Upgrades
No full textThe starting point of the research is the need to refurbish existing residential building stock, in order to reduce its energy demand, which accounts for over one fourth of the energy consumption in the European Union. Refurbishment is a necessary step to reach the ambitious energy and decarbonisation targets for 2020 and 2050 that require an eventual reduction up to 90% in CO2 emissions. In this context, the rate and depth of refurbishment need to grow. The number of building to be renovated every year should increase, while the energy savings in renovated buildings should be over 60% reduction to current energy demand. To achieve that, not only is it necessary to find politics and incentives, but also to enable the building industry to design and construct effective refurbishment strategies. This research focuses on refurbishment of the building envelope, as it is very influential with regard to energy reduction.
The early design phases are particularly important, as decisions taken during this stage can determine the success or failure of the design. Even though the design decisions made earlier can have bigger impact with lower cost and effort, most existing tools focus on post-design evaluation. The integration of all aspects during the early design phases is complex, particularly as far as energy efficient design is concerned. At this stage, architects are in search for a design direction to make an informed decision. If the designer is provided with an indication of how efficient refurbishment options are, it is possible to apply them as part of an integrated strategy rather than trying to add measures at later stages, after the strategy has been developed.
Therefore, taking into account the need to refurbish residential buildings and the importance of integrated design of façade refurbishment strategies, the thesis aims at answering the following question.
How can the energy upgrade potential of residential façade refurbishment strategies be integrated in the early design phase, in order to support decision-making?
The objective of the research is to enable the design of refurbishment strategies that acknowledge the potential of energy savings. Having available an assessment of the energy performance results in informed decisions that improve the efficiency of the strategy and the final refurbished building.
The answer to the research question is given by the Façade Refurbishment Toolbox (FRT) approach. It consists of three different types of information that can support the decision-making of residential façade refurbishment strategies. Firstly, the building envelope components that need to be addressed in an integrated refurbishment strategy are identified and different retrofitting measures for each one are proposed, composing the façade refurbishment toolbox. Secondly, the measures are quantified in terms of energy upgrade potential, expressed by the simulated energy demand reduction after the application of the measure. Finally, a roadmap to the key decision aspects in the refurbishment strategy development indicates when the toolbox information can be used.
The methodology used to develop the FRT approach includes organising and calculating information about component retrofitting measures. The steps of the methodology were developed in the different chapters of the thesis. The first three chapters (Chapters 2-4) comprise the theoretical background that shapes the research question, discussion of the residential building stock, energy performance and refurbishment practice. Chapters 5 and 6 describe the process of the composition of the toolbox. Finally, Chapters 7 and 8 are concerned with its further applicability, regarding the approach validation and usability.
This thesis concludes with an approach to enable informed and energy-efficiency conscious decisions in the early stage of the design of refurbishment strategies. To improve the design process, the Façade Refurbishment Toolbox facilitates the development of strategies in different cases and for different specifications, without limiting or dictating designers’ choices.
Designing is deciding. Knowledge and information can lead to better understanding of a decision consequent and, therefore, result in better design solutions. Different buildings have different energy saving potential. They also have different specifications, performance requirements and design ambitions. All these parameters result in different refurbishment strategies. The aim of the proposed approach is not replacing the design process and generating a solution, but supporting it by providing information to lead into responsible and knowledgeable decisions. In this way, refurbishment strategies that take into account the building improvement, occupants’ comfort and efficient energy use can be designed, contributing to the greater society’s goals of CO2 emissions reduction and sustainable development
Dwelling on Courtyards: Exploring the energy efficiency and comfort potential of courtyards for dwellings in the Netherlands
Get PDFThe urban heat island (UHI) phenomenon and the dependency of buildings onÀ¨fossil fuels were the two main issues that formed this dissertation. UHI results in higher air temperatures in dense urban areas compared with their suburbs and rural surroundings. This phenomenon affects human health through thermal discomfort. Furthermore, in the Netherlands, it is estimated that by 2050 the air temperature could be up to 2.3°C warmer as compared to the period of 1981-2010. Besides, the energy consumption of buildings is responsible for 30 to 45% of CO2 emissions. 31% of this consumption belongs to residential buildings. Residential buildings can play a major role in reducing the CO2 emissions caused by fossil fuel consumption.
One of the passive architectural design solutions is the courtyard building form. Courtyards have been used for thousands of years in different climates in the world. In hot climates they provide shading, in humid climates they cause a stack effect helping ventilation, in cold climates they break cold winds and protect their microclimate. In temperate climates (such as of the Netherlands), the thermal behaviour of courtyards has been studied less. In this dissertation, low-rise residential courtyard buildings were therefore studied among (and along) different urban block types in the Netherlands.
As the first step, computer simulations were done as a parametric study for indoor and outdoor thermal comfort. Field measurements were done in actual urban courtyards and in dwellings alongside urban courtyards in the Netherlands (and in a similar temperate climate in the US). A scale model experiment later followed the simulations. Some of these field measurements were used to validate the simulation models. These efforts answered the two main research questions:
1) To what extent is a dwelling alongside an urban courtyard more efficient and thermally comfortable than other dwellings?
2) To what extent do people have a more comfortable microclimate within an urban courtyard block on a hot summer day than within other urban fabric forms?
To answer the first question, the energy performance of and thermal comfort inside dwellings in three types of urban blocks in the Netherlands (each with 1, 2 and 3 stories) were analysed (with an identical floor area). The main objective of the research was to clarify the effect of building geometry on annual heating energy demand, thermal comfort, heat loss, solar gains through external windows and on overheating in summer. The buildings had different surface to volume ratios owing to different shapes: single, linear and courtyard shape. The single shape model is more exposed to its outdoor environment and has the highest surface to volume ratio. The linear models consist of a row of dwellings, which leads to a smaller area exposed to the outdoor environment, and this amount is the lowest for the courtyard models. The single dwelling has a higher surface to volume ratio and this model has the highest solar gains. The average amount of energy demand for heating in a year for the single shape is the highest among the models. However, the lighting energy demand for the single shape is the lowest. The linear and courtyard models are very similar in lighting energy demand. The courtyard shape has the lowest energy demand for heatingˬsince it is more protected. Considering thermal comfort hours in free running mode, the courtyard shape has the lowest number of discomfort hours among the models. Reducing the external surface area exposed to the climatic environment leads to higher energy efficiency and improved summer thermal comfort performance. Therefore, this analysis showed that the courtyard shape proves to be more energy efficient and thermally comfortable than other dwellings.
For the second research question, the microclimate within the urban block forms previously studied (singular, linear and courtyard) were simulated, each with two different orientations (E-W and N-S, except for the courtyard). To explore their microclimates the simulations were done for the hottest day in the Netherlands (19th June 2000) according to the temperature data set provided in NEN5060. The results showed that the singular forms provide a long duration of solar radiation exposure for the outdoor environment. This causes the worst comfort situation among the models at the centre of the canyon for a hot summer day. In contrast, the courtyard provides a more protected microclimate which has less solar radiation in summer. Considering the physiological equivalent temperature (PET), the courtyard has the highest number of comfortable hours on a summer day. Regarding the different orientations of the models and their effect on outdoor thermal comfort, it is difficult to specify the differences between the singular E-W and N-S forms because they receive equal amounts of insolation and are equally exposed to wind. Nevertheless, the linear E-W and N-S forms are different in their thermal behaviour. The centre point at the linear E-W form receives sun for about 12 h. In contrast, this point at the linear N-S form receives 4 h of direct sunlight in that day. Therefore, in comparison with the E-W orientation this N-S orientation provides a cooler microclimate.
To sum up the above findings, it should be said that this study showed that courtyard buildings as a passive design solution (originally from hot and arid climates) can improve energy efficiency and thermal comfort for Dutch dwellings. This building archetype can reduce energy demands for cooling, as a result being a good alternative form for the expected warmer future of the Netherlands. Designing small scale courtyards (single- family house) needs attention in winter. Courtyards provide more indoor and outdoor comfort in comparison with linear and singular forms. With this knowledge, it could be said that design strategies taken from one climate may be applicable in other climates but with serious attentions and modifications. Different disciplines and sciences can perform valuable roles to make this transition beneficial for the fragile ecosystem and people