Dissertations

• 

  Partnering for climate change adaptations by Dutch housing associations

  Climate change can no longer be ignored. It is globally recognised that the evidence for climate change is unequivocal and that action needs to be taken in order to address its negative effects.

  These effects, such as warmer and drier summers and more extreme rainfall, may threaten the quality of life of those living in urban environments. To limit these threats, a number of climate change adaptation measures can be taken to pre-empt the negative effects of climate change.

  The challenge of increasing the implementation of climate change adaptation measures is addressed in this thesis by engaging the construction sector while focusing on the housing stock that is owned and maintained by Dutch housing associations. By implementing climate change adaptation measures, dwellings will become more resilient to some of the effects of climate change, becoming less vulnerable for damage and ensuring the comfort, safety and quality of life of their occupants. Because housing associations are regarded as societal entrepreneurs, these are expected to use resources and commercial profits to achieve societal aims that are in the common interest, such as making timely adaptations, so that changing climatic conditions cannot threaten the quality of their dwellings. Moreover, there are relatively few housing associations compared to the number of houses they own and maintain. In 2012, there were 381 housing associations that owned and maintained a stock of 2.4 million dwellings, representing 32% of the total Dutch housing stock. This means that approaching the Dutch social rented sector was seen as an effective way of generating a greater societal impact.

  In the past decade, external influences such as the recent economic crisis and political pressure, have led housing associations to become more cost effective and to make changes in their organisational strategies, which has resulted in the adoption of more integrated project delivery methods, such as partnering. These integrated methods aim to involve the construction sector early in the development of plans so that they can contribute their expertise. This creates a more efficient construction and maintenance process and delivers dwellings of higher quality.

  The housing associations cannot pre-empt all the effects of climate change alone. For adaptation measures at the neighbourhood level, they are dependent on collaboration with other stakeholders such as municipalities, but there are measures that can be applied at the building level, which falls within their range of influence. An example is the application of lighter colours on building façades in order to reflect radiation and reduce the air temperature close to the façades. The hazards of overflowing sewage systems caused by extreme precipitation can be reduced by applying measures to retain water temporarily, such as ‘green roofs’ or to ensure effective drainage such as open pavements. These measures reduce the peak load on the sewage system. Another effective measure is the use of materials that are not negatively affected by water so that if, despite all the precautionary measures, flooding does occur, the consequences would be less severe.

  Problem formulation

  This research assesses the potential of adopting a partnering approach as a governance tool with which to increase the implementation of climate change adaptation measures like those described above. The housing stock owned by Dutch housing associations is taken as a case study. Involving the construction sector through a partnering approach is promising, since construction companies are the ones who carry out the works. Their early commitment reduces the risks of miscommunication or  failure and enhances opportunities for innovative solutions. By doing this, not only do housing associations take responsibility for their actions, but the construction sector as a whole gains more responsibility for solving societal challenges and is enabled to co-create solutions that can then be disseminated more easily.

  The main research question is: How can partnering in construction increase the implementation of climate change adaptation measures in dwellings owned by Dutch housing associations?

  Research approach and results

  To formulate an answer to this research question, several separate studies were conducted. First, the characteristics of three types of governance were studied in a literature review, these being hierarchic, market and network governance. Based on these types of governance, many tools have been developed over time, but to increase the implementation of climate change adaptation measures in social housing, not all tools are equally successful, at least not from a theoretical point of view. To improve the implementation of measures, tools could be combined to create a more solid basis for action, and there is room for extra governance tools in the current palette.

  Based on the literature review on partnering, it was concluded that this could be classified as a combined ‘market’ and ‘network’ type of tool. The market aspect refers to the knowledge of climate change adaptation that is gained by the participating construction companies, which can imply a competitive advantage for them. The network aspect is closely linked to collaboration within a partnering approach. In other contexts, the partnering approach has been shown to remove the barriers of fragmentation in the construction sector; to provide for a more efficient and integral construction process, and to allow for the easier flow of knowledge on climate change adaptation.

  Next, the current state of knowledge among housing associations was studied with regard to climate change adaptation measures for the housing stock. A content analysis was conducted on the annual reports and policy plans of the 25 largest Dutch housing associations and revealed that they display no awareness of climate change adaptation in their policy documents. As such, they were categorised as ‘unaware’. However, this does not mean that the building stock is not being adapted to climate change, because in the annual reports they state that they have applied climate change adaptation measures, although they do not name these as such. This means that applying adaptation measures is neither impossible nor unrealistic, as long as they are not implemented solely for climate change adaptation purposes, but for other reasons as well, such as energy-efficiency.

  In contrast to the corporate policy documents, interviews with individual policy-makers showed that housing associations are aware of climate change at a global scale. However, in relation to climate change adaptation measures in their daily work, such as the impact of flooded streets and overheating interiors of dwellings, awareness is low. They could not name many threats or adaptation measures. However, once they had been made aware of the need for such measures, the employees were fairly well capable of assessing them, even though the implementation of measures was evaluated as unfeasible in most cases. The main reason provided was that the housing associations did not have policy guidelines in place for such adaptation measures. Moreover, in many cases there were financial and/or technical barriers that would have to be addressed first. There was a consensus among employees that all the measures would have a positive effect on the comfort of the dwellings.

  Partnering in construction can help to increase the implementation of adaptation measures because it can overcome many of these challenges. For this reason, the way that housing associations and construction companies carry out refurbishment projects in a partnering approach was also studied. The researcher participated in a knowledge exchange project in which housing associations and construction and maintenance companies had formed dyads and carried out a refurbishment project. They exchanged their experiences on a regular basis through interviews and plenary sessions.

  In the interviews, employees of housing associations and construction and maintenance companies were asked how they dealt with the success factors for partnering, which were derived from literature. These success factors were trust, leadership, partner capabilities, commitment, conflict resolution, coordination and communication.

  Although they did not address all these success factors equally well, the study showed that Dutch housing associations and construction and maintenance companies are indeed capable of carrying out housing refurbishment projects in a partnering approach. This allows for the selection of the construction process as a governance tool with which to implement climate change adaptation measures. These measures are considered new products that can be installed with the aim of improving the technical and functional quality of dwellings. In that sense, they are perceived as product innovations, with the dwellings being the ‘products’ and/or assets of the housing associations. This perspective corresponds with the definition1: “[An innovation is] a new idea that is implemented in a construction project with the intention of deriving additional benefits although there might have been associated risks and uncertainties. The new idea may refer to new design, technology, material component or construction method deployed in a project”. 

  Subsequently, the employees of the housing associations and construction and maintenance companies were asked how they dealt with the implementation of innovations using surveys. Although several studies indicate that innovation can benefit when projects are based on an integrated construction process such as partnering, the current study concludes that partnering does not automatically lead to product innovation. Most of the respondents saw partnering itself as the innovative aspect of their projects – i.e. a process innovation. That process innovation required so much attention that there was less emphasis on opportunities for product innovations. This should be taken into account when developing governance tools to encourage the implementation of product innovations in dwellings such as climate change adaptation measures. 

  Moreover, the choice of partnering as a project delivery method as a governance tool is less likely to resolve issues regarding policy, which remain a barrier for the implementation of measures. In addition, other parties can also become involved, to generate resources for the implementation of measures by housing associations. The adoption of partnering as a project delivery method is therefore not the only possible governance tool.

  To increase the implementation of climate change adaptation measures, two more conceptual approaches were developed by the researcher in addition to the initially hypothesised partnering approach. These additional conceptual approaches involved policy development by housing associations vis-à-vis climate change adaptation measures and collaboration with external actors who face the same challenges in order to enhance efficiency in solving these issues together. The feasibility of the three conceptual approaches was verified by means of a SWOT analysis performed with practitioners from housing associations and construction companies as well as external players such as water authorities, insurance companies and municipalities. The results of the SWOT analysis made it clear that single-pronged conceptual approaches are unlikely to be successful because they involve serious weaknesses or threats. A combination of conceptual approaches is much more likely to remove the barriers that obstruct the implementation of climate change adaptation measures.

  The conceptual approaches were therefore combined and renamed as implementation strategies. In on-line questionnaires carried out among all Dutch housing associations, it was assessed if the housing associations found it likely that these strategies would indeed lead to the implementation of climate change adaptation measures. In general, the respondents assessed the feasibility of all strategies as unlikely to neutral. There was no strategy that clearly stood out as more feasible for the implementation of climate change adaptation measures. However, a considerable number of housing associations assessed one or more implementation strategies positively and saw opportunities for the implementation of measures, albeit framed differently, such as measures to increase energy-efficiency or enhance comfort.

  Conclusion

  Based on the findings outlined above, the answer to the main research question is: Partnering in construction can increase the implementation of climate change adaptation measures in dwellings owned by housing associations, when it is understood as a catalyst for information-sharing and increased efficiency in the construction process.

  By looking for shared interests between housing associations and the construction sector, the chances of implementing adaptation measures increase. However, if other stakeholders are involved as well, and if housing associations embed climate change adaptation in their policy guidelines, the likelihood of implementation would increase even more. Although none of the implementation strategies stood out clearly as the strategy most likely to result in the implementation of climate change adaptation measures, a considerable number of housing associations assessed various implementation strategies positively.

  If the construction process becomes more network-based, which is the case when a partnering approach is adopted, many more parties can become involved and contribute to the implementation of climate change adaptation measures. In such a situation, it no longer matters who introduces the subject during the plan development and construction process, as long as it ends up there and action is taken. To implement these measures more easily, the framing is very important. Climate change adaptation is not enough reason in its own right to begin implementing measures. Insulation to prevent overheating in the summer is considered an ‘extra’ measure - the necessity of which is still questioned by policymakers, for example. However, if the same measure is framed as an energy-saving measure, it is also a cost-cutting measure, which increases the likelihood that policymakers will start making plans to implement it!

  Scientific implications of the results

  This thesis has contributed to the development of governance tools to increase the implementation of climate change adaptation measures in dwellings, while current adaptation strategies predominantly target the national or local levels of the built environment. Moreover, this thesis has examined the adoption of partnering as a project delivery method and a governance tool with which to bridge the theoretical fields of network governance and integrated construction and maintenance processes. It extends the palette of governance tools that traditionally consists of information tools, tools relating to the division of property rights, incentives and regulatory tools. It has proven that housing associations can successfully adopt partnering approaches. As such, partnering is a feasible approach by which to increase the implementation of innovative measures such as climate change adaptations.

  Practical implications

  The assessment of the five implementation strategies showed that adapting housing for climate change has a low priority as a separate policy field. It is a relatively new area for policymakers, so they may be reluctant to believe that measures are likely to be implemented. Moreover, many other topics may take a higher priority for them, such as improving energy-efficiency and thereby also the affordability of dwellings, and/or preparing the dwellings for an ageing population. In the literature on climate change adaptation, it is suggested that mainstreaming climate change adaptation is the best course, which implies attaching the adaptation policy to existing policy frameworks. This would make policymakers aware of the topic of climate change adaptation and they could look for synergies between measures that were already planned and measures related to climate change adaptations.

  The refurbishment and maintenance process of housing associations provides opportunities for the mainstreaming of adaptation measures. Housing associations are facing an ageing stock that needs to be improved if it is to continue to meet the ever increasing basic requirements of tenants in terms of quality and comfort and increasingly strict energy-efficiency standards. Since climate change is occurring gradually, there is still time to adapt the building stock gradually, in step with the renovation and maintenance cycles of the housing associations.

  Bringing in external players, especially municipalities and water authorities, would appear to be a highly feasible approach, given their shared interest in the quality of life in local areas. Bringing together the construction partners requires governance tools that inform them of the benefits of partnering. Particularly if construction companies are to be responsible for the renovation and the maintenance for the rest of the service life of the dwellings, they could focus on improved design solutions that aim to create resilient dwellings, and/or using materials that would be less affected by the effects of climate change. The role of tenants in the implementation of climate change adaptations is primarily that they might exert ‘bottom-up’ pressure by requesting action from housing associations. But for this to happen, they would likely need to be informed about the effects of climate change on their dwellings and/or neighbourhoods, in order for them to be motivated to ensure that their homes are climate change resilient.

  Climate change can no longer be ignored. It is globally recognised that the evidence for climate change is unequivocal and that action needs to be taken in order to address its negative effects.

  These effects, such as warmer and drier summers and more extreme rainfall, may threaten the quality of life of those living in urban environments. To limit these threats, a number of climate change adaptation measures can be taken to pre-empt the negative effects of climate change.

  The challenge of increasing the implementation of climate change adaptation measures is addressed in this thesis by engaging the construction sector while focusing on the housing stock that is owned and maintained by Dutch housing associations. By implementing climate change adaptation measures, dwellings will become more resilient to some of the effects of climate change, becoming less vulnerable for damage and ensuring the comfort, safety and quality of life of their occupants. Because housing...

  Climate change can no longer be ignored. It is globally recognised that the evidence for climate change is unequivocal and that action needs to be taken in order to address its negative effects.

  These effects, such as warmer and drier summers and more extreme rainfall, may threaten the...

  Martin Roders

  • Download dissertation
• 

  Urban Climate Design: Improving thermal comfort in Dutch neighbourhoods

  This thesis presents research into the possibilities for climate adaptation in Dutch urban areas. We want to know how cities can best prepare for extreme rainfall, droughts, and heat waves in future climates. These events are likely to become more frequent and more extreme. The focus is on heat resistance as this has been a neglected concept in Dutch urban planning.

  The aim of this study is to extend our knowledge of the effects of climate-adaptation measures and to stimulate the implementation of such measures in the design of public space. Anticipating on the effects of climate change, the research was guided by the question: Which urban design principles can be applied in specific Dutch neighbourhoods to respond to the effects of climate change, especially in terms of outdoor thermal comfort and water management?

  The three stages of the project are: 

  1. A literature review of existing knowledge on climate adaptation and knowledge gaps
  2. Research into the specific field of urban climatology
  3. Applied research on the broader field of urban planning

  The urban climate and adaptation measures

  In the evaluation of measures for climate robust urban areas it is important to gauge the extent of the effects of such measures. These effects are generally expressed in terms of air temperature. However, the comparison of results of measures from various studies is not a simple matter: there are significant differences in spatial, climatological and methodological variations adopted in these studies. Bringing results together from very specific studies may give an impression of the potential of certain measures. For example, most studies support the idea that greening has the highest effect on thermal comfort as it provides both shade and active cooling due to ‘evapotranspiration’1. Nevertheless, vegetation can also retain heat, as we can feel after sundown. Other measures that were investigated for their effects are water, urban morphology, materials and colour.

  Simulations and measurements

  Contextual aspects and combinations of measures can seriously influence the effects of measures. To get a grip on such effects and their co-occurrence (interrelations), possible adaptations to an existing rural configuration were modelled and their effects on the microclimate were simulated using the numerical program ENVI-met. It is demonstrated that, for instance, trees combined with highly reflective façades do often not provide cooling, whereas trees combined with moderate façade colouring does.

  To assess the effects of a single measure, independent of its context, single parameter simulations of thermal comfort (PET) were performed. This is the first time that such a comparative study was undertaken in The Netherlands. The complexity of the situations was increased gradually from an empty field with only pavement or only grass, to pavement with grass and a single building, moving up to a building with a few trees to many trees, multiple buildings and built forms. 

  During this study it became clear that airflow has a significant influence on the comfort temperature. However, cooling by means of creating drafts on a mesoscale is difficult to manage and control. The low wind speed, which is typical for Dutch heat waves, provides ventilation through thermal stratification. Airflow between warm and cool spaces only occurs with sufficient temperature differences and low wind speed. This principle was investigated on the side towards new measures because little is known about the effects of generating airflow as a result of façade colour. Measurements were performed first in a small-scale experiment in a controlled area and when results seemed promising this was extended to a full-scale situation on an average Summer’s day. 

  Research design

  In current practice, urban design pays little or no attention to the urban microclimate and urban-heat stress. Designers indicate that they have insufficient knowledge and evaluation instruments. The design study discussed in the third part of this thesis provides examples of climate adaptive applications and suggestions for design strategies.

  Using urban typologies makes it possible to integrate the microclimate in the design without needing urban microclimate expertise. By analysing specific neighbourhood typologies applying a variety of microclimate indicators three simple distinctive parameters emerge: 

  1. balance between pavement and natural surfaces;
  2. building height;
  3. built form.

  Design solutions were applied to reveal spatial implications for most of the neighbourhoods in the analysis and serve as examples and a source of inspiration. Promising and neighbourhood-specific measures were selected per neighbourhood type to support the design process.

  To demonstrate how microclimates can be managed with design choices, a design case was developed in more detail for three cities. Prioritizing measures at the design stage depends on many external and intrinsic factors. The three designs in this thesis follow the same path: analysis > maximisation > optimisation > integration. When maximization focuses on thermal comfort only design measures concerning this aspect are applied. Prioritization can be applied in a three-step strategy of: warming prevention, passive cooling and active cooling. The design process is an iterative process in which promising combinations may be found in the optimization and this may require additional analysis.

  This thesis hopes to build bridges between knowledge and science and the practice of the design of public space. That goal is approached with a product that unfolds from the three parts of the study: 

  1. Factsheets to simply check and evaluate mechanisms and affordances of measures;
  2. Guidelines for the further development of knowledge of and design with urban microclimates;
  3. A categorized set of measures to be able to select the right measure for the right neighbourhood typology.

  The study is part of a consortium of complementary research projects and stakeholders with the aim to generate knowledge through research as input for councils and other stakeholders. In addition, three participating municipal councils have gained further insight into cases that were proposed by them.

  This thesis presents research into the possibilities for climate adaptation in Dutch urban areas. We want to know how cities can best prepare for extreme rainfall, droughts, and heat waves in future climates. These events are likely to become more frequent and more extreme. The focus is on heat resistance as this has been a neglected concept in Dutch urban planning.

  The aim of this study is to extend our knowledge of the effects of climate-adaptation measures and to stimulate the implementation of such measures in the design of public space. Anticipating on the effects of climate change, the research was guided by the question: Which urban design principles can be applied in specific Dutch neighbourhoods to respond to the effects of climate change, especially in terms of outdoor thermal comfort and water management?

  The three stages of the project are: 

  1. A literature review of existing knowledge on climate adaptation and...

  This thesis presents research into the possibilities for climate adaptation in Dutch urban areas. We want to know how cities can best prepare for extreme rainfall, droughts, and heat waves in future climates. These events are likely to become more frequent and more extreme. The focus is on...

  Laura Kleerekoper

  • Download dissertation
• 

  Urban and regional heat island adaptation measures in the Netherlands

  The urban planner´s role should be adapted to the current globalised and overspecialised economic and environmental context, envisioning a balance at the regional scale, apprehending not only new technologies, but also new mapping principles, that allow obtaining multidisciplinary integral overviews since the preliminary stages of the design process. The urban heat Island (UHI) is one of the main phenomena affecting the urban climate. In the Netherlands, during the heat wave of 2006, more than 1,000 extra deaths were registered. UHI-related parameters are an example of new elements that should be taken into consideration since the early phases of the design process.

  Problem statement

  Thus, the development of urban design guidelines to reduce the heat islands in Dutch cities and regions requires first an overall reflection on the heat island phenomenom (relevance of the large scale assessment, existing tools, instruments) and proposal of integrative and catalysing mapping strategies and then a specific assessment of the phenomenom at the selected locations in The Netherlands (testing those principles).

  Main research question

  Could the use of satellite imagery help analyse the UHI in the Netherlands and contribute to suggest catalysing mitigation acions actions implementable in the existing urban context of the cities, regions and provinces assessed?

  Method

  The development of urban design principles that aim at reaching a physical balance at the regional scale is critical to ensure a reduction of the UHI effect. Landsat and Modis satellite imagery can be analysed and processed using ATCOR 2/3, ENVI 4.7 and GIS, allowing not only a neighbourhood, city and regional scale assessment, but also generating holistic catalysing mapping typologies: game-board, rhizome, layering and drift, which are critical to ensure the integration of all parameters. The scientific inputs need to be combined not only with other disciplines but often also with existing urban plans. The connection between scientific research and existing agreed visions is critical to ensure the integration of new aspects into the plans.

  Results

  At the neighbourhood level the areas that have a greater heat concentration in the cities of Delft, Leiden, Gouda, Utrecht and Den Bosch are the city centres characterised by their red ceramic roof tiles, brick street paving, and canals. Several mitigation strategies could be implemented to improve the UHI effect in those areas; however, since the city centres are consolidated and listed urban areas, the mitigation measures that would be easier to implement would consist in improving the roof albedo. A consistent implementation of albedo improvement measures (improving the thermal behaviour not only of flat roofs, but also of tiled pitched roofs) of all roofs included in the identified hotspots (with an average storage heat flux greater than 90 W/m2) would help reduce the temperatures between 1.4°C and 3°C. Pre-war and post-war compact and ground-based neighbourhoods present similar thermal behaviour of the surface cover, and green neighbourhoods and small urban centres also present similar thermal behaviour.

  At the city scale the analysis of 21 medium-size cities in the province of North Brabant, which belongs to the South region of the county -in relative terms the most affected by the UHI phenomenon during the heat wave of 2006-, reveals that albedo and normalised difference vegetation index (NDVI) are the most relevant parameters influencing the average nightime land surface temperature (LST). Thus, imperviousness, distance to the nearest town and the area of the cities do not seem to play a significant role in the LST night values for the medium-size cities analysed in the region of North Brabant, which do not exceed 7,700 ha in any case. The future growth of most medium-size cities of the regions will not per se aggravate the UHI phenomenon; in turn it will be the design of the new neighbourhoods that will impact the formation of urban heat in the province.

  The average day LST of provincial parks in South Holland varies depending on the land use. The analysis of the average night LST varies depending of the land use of the patches. The following surfaces are arranged from the lowest to the highest temperatures: water surfaces, forests, cropland, and greenhouse areas. For each of these land uses, NDVI, imperviousness and landscape shape index (LSI) shape index influence the thermal behaviour of the patches differently. NDVI is inversely correlated to day LST for all categories, imperviousness is correlated to day LST for all areas which do not comprise a significant presence of greenhouses (grassland and built patches) and inversely correlated to LST for areas with a high presence of greenhouses (cropland and warehouses). Greenhouse surfaces have highly reflective roofs, which contribute to the reduction of day LST. Finally, landscape shape index varies depending on the nature of the surrounding patches, especially for small patches (built areas, forests and greenhouse areas). When the patches analysed are surrounded by warmer land uses, slender and scattered patches are warmer, more compact and large ones are cooler. In turn, when they are surrounded by cooler patches it is the opposite: slenderer and scattered patches are cooler and more compact and larger ones are warmer. In Midden-Delfland (1 of the 6 South Holland provincial parks), most of the hotspots surrounding the park are adjacent to grassland patches. The measure to increase the cooling capacity of those patches would consist in a change of land use and/or an increase of NDVI of the existing grassland patches.

  Conclusions

  Satellite imagery can be used not only to analyse the heat island phenomenom in Dutch neighbourhoods, cities and regions (identify neighbourhoods with highest surface temperature, identify impact of city size and morphology in surface temperature, calcuate average surface temperature for different land uses…), but also to suggest mitigation actions for the areas assessed. Moreover, satellite imagery is here used to generate catalysing mapping typologies: game-board, rhizome, layering and drift, ensuring that the measures proposed remain accurate enough to actualy be efficient and open enough to be compatible with the rest of urban planning priorities.

  The urban planner´s role should be adapted to the current globalised and overspecialised economic and environmental context, envisioning a balance at the regional scale, apprehending not only new technologies, but also new mapping principles, that allow obtaining multidisciplinary integral overviews since the preliminary stages of the design process. The urban heat Island (UHI) is one of the main phenomena affecting the urban climate. In the Netherlands, during the heat wave of 2006, more than 1,000 extra deaths were registered. UHI-related parameters are an example of new elements that should be taken into consideration since the early phases of the design process.

  Problem statement

  Thus, the development of urban design guidelines to reduce the heat islands in Dutch cities and regions requires first an overall reflection on the heat island phenomenom (relevance of the large scale assessment, existing tools, instruments) and proposal of integrative and...

  The urban planner´s role should be adapted to the current globalised and overspecialised economic and environmental context, envisioning a balance at the regional scale, apprehending not only new technologies, but also new mapping principles, that allow obtaining multidisciplinary integral...

  Leyre Echevarria Icaza

  • Download dissertation