Selecting Switzerland

Abstract

The study design of this book is based on four case studies located in Switzerland: the four cities—Zurich, Basel, Köniz, and Kloten—where a concrete densification area is analyzed. Through this case study design, objectives of broadness of scope and analytical depth are reached. Chapter 4 entangles what is specific to each case study and which observations are of broader significance. First, the Swiss context of the empirical analysis is described, then the detailed reasons for case selection, as well as the different data collection and analysis methods applied. Lastly, this chapter is concluded by reflecting upon the researcher’s own positionality in the research process and the various challenges encountered in the field.

4.1 Study Design and Methodology: Densification and Urban Housing Development in Switzerland

To explain the governance mechanisms at play leading to socially sustainable housing development in dense city areas (main research question), the data of the four articles of this book is conducted through a qualitative case study design. A case study is “an empirical inquiry that investigates a contemporary phenomenon in depth and within its real-life context, especially when the boundaries between the phenomenon and the context are not clearly evident” (Yin, 2018: 15). This qualitative approach makes it possible to uncover new trends and individuals’ motivations in order to grasp a largely unknown and barely quantifiable process of social origin (George & Bennett, 2005; Taylor & Bogdan, 1998). It acknowledges that social sustainability in housing is produced by a complex interplay of contextual (institutional setting) and behavioral factors (actors’ strategies). Housing development in dense urban environments cannot be separated from its context and thus requires a qualitative analysis (Flyvbjerg, 2006; Yin, 2018). By employing a qualitative case study design, the research questions (SQ1–3) are answered as results of human action and within its real-time socio-economic and -political context (Scholz & Tietje, 2002).

However, case study research also aims at generalization. It is connected to relational approaches in urban studies aiming to identify similarities and/or differences in local patterns of policy implementation (Robinson, 2016; Ward, 2010). Deductively developed research variables—such as in this book, housing as a resource, institutions, and actors’ strategies—postulate causal mechanisms (Sect. 3.7) that are investigated in the light of the empirical material collected in carefully selected cases (Sect. 4.3). Potential for generalization is not obtained through testing a hypothesis for general statistical significance but rather the results from the identified causal mechanisms, the relevance of which is expected to be broader than in the analyzed cases only (Flyvbjerg, 1998, 2006; Yin, 2018).

In the following section, I describe the Swiss context of the empirical analysis (4.2), the detailed reasons for case selection (4.3), as well as the different data collection and analysis methods applied (4.4). I conclude this chapter by reflecting upon my own positionality in the research process and the various challenges encountered in the field (4.6).

4.2 Study Context: Challenges of Housing, Urban Land Scarcity, and Social Exclusion in Switzerland

The present research is first and foremost based on a Swiss case study. The country counts 8.6 Mio. residents in total (FSO, 2020b) and is internationally considered a small state of only 41.285 square kilometers located in the center of Europe. Given the fact that much of the land cannot be or is not used for residential purposes due to landscape protection or mountainous surfaces, the effective population density is substantially higher than is average across Europe (Bourassa et al., 2010: 266). Consequently, Switzerland today has an urbanization level of about 73% (Weilenmann et al., 2017: 469).

The state makes a promising case study to gain knowledge on housing use conflicts as results of densification since the socio-economic challenges connected to urban growth have increased substantially in recent years (see Article 1 for details). Between 1935 and 2002, the degree of urban sprawl in Switzerland increased by 155%, and without effective policy measures, quantitative scenarios of future urban sprawl show that it is likely to further increase by more than 50% until 2050. Between 2002 and 2010, moreover, the degree of greenfield development was around three times as high as between 1980 and 2002 (Jaeger & Schwick, 2014: 294).

To reconcile concerns of urban sprawl, the Swiss federal government has introduced spatial development guidelines (the revised Federal Spatial Planning Act [SPA] in 2013) more in line with environmental sustainability in a span of more than 20 years (Swiss Federal Council, 2016). General principles include the restriction of urban sprawl, the reduction of energy emissions, and the support of a more compact urbanization (Rérat, 2012a: 116–120). Stated another way, densification has become a major issue in professional and planning circles as well as in the broader population, but there is still much questioning and concern that stands in the way of implementation at the municipal level (see Articles 2–4 for details) (Grams & Nebel, 2013; Nebel et al., 2017; Rérat, 2012a: 129; Swiss Federal Council, 2017). In sum, we are in the light of facing severe socio-spatial challenges linked to the end of greenfield development in this country.

Furthermore, the social implications of densification have become predominant in Swiss cities in recent years (Fig. 4.1). A general shift towards profit seeking in housing coupled with the obligation to densify introduced by the revised Federal Spatial Planning Act in 2013 have reinforced trends of social exclusion and gentrification in Swiss cities. In particular, old housing stocks are being demolished and redeveloped with higher rents (FOH, 2016a, 2016b; FOSI & FOH, 2015). As a consequence, a growing number of tenants living in urban rental housing stocks is confronted with eviction and displacement at short notice as they cannot afford the rents after densification and modernization tasks anymore (FOH, 2019: 4). Low- and middle-income households face difficulties in finding adequate housing as newly modernized apartments are primarily affordable for households with higher incomes, and non-profit housing suppliers have long waiting lists (Balmer & Gerber, 2017; FOH, 2017). Within the rental market, 28.9% of households suffer from excessive housing costs in relation to income (FOSI & FOH, 2015).

Fig. 4.1

Housing development in Switzerland since 1978 (Index based: 1978 = 100). While mortgage rates have constantly decreased since 1978, prices for land and rents havesteadily risen (Canton of Zurich, 2020; FOH, 2020; FSO, 2020a, 2020c; Wüest & Partner, 2020)

Simultaneously, population growth coupled with yield-oriented investments attracted by the state’s economic stability and wealth has reinforced the attractiveness of Swiss housing markets. Triggered by low-interest rates, urban housing stocks have become the main target of capital investment, especially for pension funds (Theurillat & Crevoisier, 2013; Theurillat et al., 2014). As a result, social resistance strategies against densification and large-scale investment projects have increased in Swiss cities because many tenants no longer accept the social implications caused by consolidation and upgrading (Maissen, 2018; Swiss Federal Council, 2017).

Due to these numerous reasons, Switzerland makes an interesting case study for the analysis of housing use conflicts and emerging socio-political challenges as results of densification. The federal state plays a crucial role in this matter in the sense that it signals how to deal with this issue also for cantons and municipalities. Switzerland is organized on three executive levels (municipalities, cantons, and the confederation) and characterized by a form of “cooperative federalism”. Legislation in favor of densification goals and/or social sustainability of housing is introduced by the federal state and is to be implemented by cantons and municipalities (Linder, 1994).

Hence, the three institutional levels are jointly responsible for sustainable spatial development in Switzerland but have distinct areas of responsibility (principle of “subsidiarity”). The Swiss federal government is headed by the Federal Council (executive level), which is a collegial body consisting of seven ministers. They are elected by both chambers of parliament (legislative level) which consist of the National Council (representing the people) and the Council of States (representing the cantons). In general, the Swiss political system is characterized by direct democratic rights including the use of initiatives and referendums on all administrative levels (Bourassa et al., 2010: 268).

4.3 Case Selection: Housing Under Densification Pressure in Four Swiss Cities

To understand how housing is shaped in a context of densification, four Swiss case studies for detailed analysis were selected. The four cities—Zurich, Basel, Köniz, and Kloten—were chosen due to multiple reasons. First, the four municipalities were selected along the dependent variable of the main research question (social sustainability in housing). At the time of investigation, all four cities had to deal with ongoing housing challenges as results of urban densification projects. They all showed similar socio-economic characteristics such as strong population growth, scarcity of urban land, intensive densification pressure, affordable housing shortages, and challenges of new-built gentrification (Table 4.1). They moreover represented highly urbanized environments where most people live, where most economic development takes place, and where most housing projects are obtained. Hence, these cities are part of a highly integrated urban system in Switzerland in which the municipalities present regional centers for economic activities and living—similar to the urban structure in Germany or the Netherlands (Fig. 4.2). Therefore, by choosing these municipalities, the governance mechanisms at play (independent variable) leading to socially (un)sustainable housing development in a dense urban environment (main research question) became easily visible and graspable (Yin, 2018).

Table 4.1 Housing market characteristics in Zurich, Basel, Köniz and Kloten City (City of Kloten, 2020b; City of Köniz, 2020b; FOSD, 2017: 25; FSO, 2020b; Glattal Region, 2020; Nebel et al., 2017; Statistical Offices Zurich & Basel-City, 2019, 2020)

Fig. 4.2

Map of Switzerland and the cases conducted within the country—Zurich, Basel, Köniz, and Kloten (own figure)

Second, while general densification objectives can be defined at a broader federal or regional scale, real-time implementation needs to be undertaken at the projects level, block by block, dealing with each impacted landowner one by one. To investigate concrete examples in the cases under scrutiny, I further selected cities that are currently challenged by concrete residential densification projects (opportunism). A (re)development area was defined as a set of buildings that belong to a private legal body and for which this body has a certain strategy to manage them (Fig. 4.2). In general, these densification areas were selected according to:

• The type of dominant use: residential.

• The type of landownership: private rental. Institutional investors own 63% of the housing stock property in Swiss cities. This ownership type is identified to be representative of many other residential housing areas in Swiss urban areas (FOH, 2017: 14).

• The project’s actuality: implemented within the last five years (2015–2020). Thereby, I was able to directly confront the actors involved with their decisions and actions taken in order to understand how they cope with social sustainability challenges in housing under scarce land use conditions (see research questions).

Third, despite its similarities (e.g. housing challenges, densification pressure, population growth) the four cases also showed some distinct differences in terms of their local governance mechanisms (main research question). To compare and to assess the variation in their social, political, and institutional structures (independent variable), I selected municipalities in order to study and to understand differences in the local institutional context (SQ1) and applied actors’ strategies (SQ2). Even though there are various public actors—at the national, regional, and local level—whose decision-making directly shapes and (re)defines the housing landscape, in liberal states such as Switzerland, the municipality is the public actor mainly responsible for addressing social challenges in housing (Rudolf et al., 2018: 476; Schönig, 2020). As regulators, municipal authorities (administrative level) on behalf of the city council (executive level), and the city parliament (legislative level) create, control, or dictate housing use rights. With respect to regulations on higher levels (e.g. Federal SPA), municipal authorities are in charge of granting building permits for residential densification projects to private landowners and building applications always need to align with the municipal zoning plan and its associated building ordinance (Bühlmann et al., 2011; Muggli, 2014).

I selected two urban core cities—the cities of Zurich and Basel (>100,000 inhabitants)—and two suburban cities—Köniz and Kloten (>20,000 inhabitants). While in core cities, authorities can usually rely on well-organized administrative units, smaller municipalities often have less capacity due to the lack of planning experts working in their administration. They are also confronted with a faster turnover among politicians, at both executive and legislative levels (Rudolf et al., 2018: 477). To understand how municipal governance works, I therefore selected four municipalities of different sizes and administrative structures to develop a broad understanding of the implementation of densification objectives in different urban contexts (Fig. 4.3).

Fig. 4.3

Densification areas within the four municipalities studied—Basel Schoren (top left), Kloten Southern district (top right), Köniz Nessleren (bottom left), and Zurich Brunau (bottom right) (own figure)

4.3.1 The Case of Zurich City

The city of Zurich is a German-speaking city and the largest urban center in Switzerland (434,008 residents around 1 Mio. including the suburbs) (Statistical Office City of Zurich, 2020). The municipality of Zurich represents both the core center of Zurich agglomeration and the capital of the canton of Zurich. Due to its steady population and economic growth and its function as an international investment center, Zurich is considered Switzerland’s financial capital (Theurillat & Crevoisier, 2013). It is moreover a metropolitan center characterized by a high degree of urbanity. For years, alongside Geneva, Zurich has been listed as one of the cities with the highest quality of life and at the same time the highest cost of living worldwide (Rérat & Lees, 2011: 131).

Since 1980, Zurich’s population has increased by +17%, and investment in real estate has constantly risen (Statistical Office City of Zurich, 2020). During the 80s and 90s, Zurich started to deindustrialize and some of the abandoned industrial land was transformed into office development or was taken over for cultural activities. A major process of reconstruction began in which the municipality started to transform from “no-man’s land” into a fashionable city. Many investors and developers have begun to recognize the city’s potential and started to reclaim the buildings they owned (Rérat & Lees, 2011: 131).

Since the year 2000, however, the redevelopment of existing buildings or vacant plots has become increasingly challenging for investors due to conflicting land use interests at central locations. Only 10% of all newly built apartments have been built on unbuilt parcels during the last two decades in Zurich. Most of the newly built dwellings have been created through reconstruction and densification of existing housing stocks on already built land (e.g. through renovation, transformation) since free inner-city greenfield and brownfield areas are missing (City of Zurich, 2020). Therefore, the tensions between densification and social exclusion mechanisms have increased significantly in recent years (Rérat, 2012b). The absolute number of social evictions in the city’s private rental sector has doubled within the period of 2006–2017 (Statistical Office City of Zurich, 2017). Between 2000 and 2013, rental prices in the housing stock have increased by 37% while rental prices on the free market have risen even more drastically, by 75% (Balmer & Gerber, 2017: 8). Moving to cheaper suburban areas has remained the main option to afford housing for many vulnerable and lower income groups living in Zurich.

4.3.1.1 Zurich Brunau

Research conducted in the city of Zurich focused on a residential area close to the center called “Zurich Brunau”, a former clay pit and industrial zone (Figs. 4.4 and 4.5). Like many other parts of the city, the area was deindustrialized and transformed during the 1980s (Rérat, 2012a: 119). Since then, a series of new housing developments of a hundred units or more have been constructed. Specifically, Zurich Brunaupark—a settlement built in the 1980/1990s—is comprised of four residential buildings with 239 apartments and approximately 400 residents. It is situated next to the Sihlcity mega-project, which opened in 2007 as the first big urban entertainment center in Switzerland. Sihlcity is a shopping and leisure facility including almost 80 shops, nine cinema screens, a spa, a library, a hotel, a church, restaurants, several offices, and apartments (Theurillat & Crevoisier, 2013: 2062).

Fig. 4.4

Map of Brunaupark settlement located at the South-Western part of the City of Zurich (top), and two pictures of the inner-yard of settlement itself (below) (Sources GIS data system, Canton of Zurich, 2022; own photographs)

Fig. 4.5

Map of Brunaupark settlement located at the South-Western part of the City of Zurich (top), and two pictures of the inner-yard of settlement itself (below) (Sources GIS data system, Canton of Zurich, 2022; own photographs)

The pension fund of the bank “Credit Suisse” (CS) plans to demolish the inner-city location by replacing old buildings from the 1980s and 1990s. Four of the five buildings will be demolished and replaced by seven-storey residential buildings instead of today’s five-storey residential buildings (potential for exploitation of +30,000 m²). The number of apartments in the four new buildings will increase from 239 today to 497 in the future (Schoop et al., 2020: 18). In March 2019, the planning application was submitted to the Zurich Office for Building Permits. This was followed by the contract termination for a total of 239 tenant parties. Within a year, around 450 people would have to leave their homes (Schoop et al., 2020). In 2012, two of the four buildings in the settlement were refurbished, namely, kitchens and bathrooms were redone. Following the planned demolition and new construction, rents are expected to rise by around +60%. According to the investor, a 3.5 room apartment (75 m²) will cost between 2200 and 2650 CHF monthly net rent (today about 1500 CHF net).

4.3.2 The Case of Basel-City

The city of Basel is a German-speaking city and after Zurich and Geneva the third largest urban center in Switzerland (178,445 inhabitants; around 800,000 including suburban areas) (Swiss Cities Association, 2020). Basel-City is also the capital of the canton of Basel-Stadt, which it forms with the municipalities of Riehen and Bettingen. Basel is moreover a border town located on the Northern border of Switzerland at the triangle between Switzerland, Germany, and France. The city therefore has suburbs in all three countries. Basel is divided into “Grossbasel” on the left (Southwestern) side of the Rhine River and the area of “Kleinbasel” on the right (Northeastern) riverbank of the Rhine. The municipality is considered a global center for the chemical and pharmaceutical industry. Two large international pharmaceutical companies “Novartis” and “Roche” have their headquarters in Basel.

From a spatial development perspective, Basel-City has undergone a period of structural change and intensive population growth since the 1990s (Ott, 2020). Since 2000, the city population has increased by +7% to 178,445 in total (Statistical Office City of Basel, 2020). By 2040, Basel’s residential population is expected to increase by another 10%. The city currently faces a shortage of affordable housing. Between 2003 and 2013, rents in existing stocks have increased by 29%. Rental prices offered on the free market have increased even more dramatically, by 38% (Balmer & Gerber, 2017: 8). An increasing number of socially disadvantaged groups find it difficult to find an apartment within city boundaries (Basel-City Council, 2018: 6). To address these challenges, the city government has initiated the “1000+” housing program, which aims to create a total of 1000 newly built affordable apartments in public ownership by 2035. In addition, many former industrial sites have been redeveloped or are currently being transformed into housing areas (Ott, 2020; Statistical Office City of Basel, 2019: 6).

4.3.2.1 Basel Schoren

The empirical analysis conducted in the city of Basel focused on a residential area close to “Basel Badischer Bahnhof”, situated at the Northeastern edge of the city center. The “Schoren” area includes some newly built developments of different sizes on former brownfield sites or on vacant land, but also the redevelopment of already densified land. Around 1400 inhabitants currently live in the Schoren neighborhood, and the population is expected to grow steadily in the next few years. In particular, the relocation of the former Novartis office campus has created vacant industrial space that has now been designated to be transformed into a large-scale residential area. From 2012 to 2018, an additional 800 residents moved to the Schoren area, which meant a population increase of almost +30% (City of Basel, 2015: 2). Specifically, I focused on the Basel Schorenweg area—a settlement built in 1961—which counts 196 apartments with around 300 residents in total. The Credit Suisse investment fund plans to densify the two buildings via total internal reconstruction with smaller housing units in 2021 (Laur, 2019: 21) (Figs. 4.6 and 4.7.

Fig. 4.6

Map of Basel Schorenweg settlement located at the North-East part of the City of Basel (top), and pictures of the inner-yard of settlement as well as renovated kitchens and bathrooms (below) (Sources Geodata Canton Basel-City 2021/2023; own photographs)

Fig. 4.7

Map of Basel Schorenweg settlement located at the North-East part of the City of Basel (top), and pictures of the inner-yard of settlement as well as renovated kitchens and bathrooms (below) (Sources Geodata Canton Basel-City 2021/2023; own photographs)

4.3.3 The Case of Köniz City

Köniz is a German-speaking municipality in the “Bern-Mittelland” administrative district in the canton of Bern in Switzerland. The municipality is part of the wider agglomeration of the city of Bern. Köniz is located southwest of Bern center and is the fourth largest municipality in the canton of Bern and the thirteenth largest town in Switzerland with 42,694 inhabitants in total (City of Köniz, 2020a). Between 2003 and 2013, the residential population in Köniz increased by 7%, which is more than in the surrounding municipalities. The increase has primarily to do with the proximity of Köniz to Bern and immigration from abroad. In principle, the majority of the households living in Köniz can afford an apartment on the rental market. However, it is assumed that, due to high demand and scarce land use conditions in the municipality, the housing situation will worsen in the future. Prices on the housing market tend to rise, which primarily affects family households and lower income groups (Beck et al., 2016: 14–15).

4.3.3.1 Köniz Nessleren

Research conducted in the city of Köniz focused on the “Nessleren” area located in the Wabern district at the northeastern edge of the municipality. The settlement consists of 33 houses that were built between 1979 and 1982. The three-story buildings are arranged in 13 rows of two or three houses. The three institutional owners of the settlement (one private foundation, one private bank, and one private insurance company) decided to remedy the existing structural deficits, in particular, the insulation and heating system through reconstruction. The buildings were completely renovated and densified in 2018. The settlement now counts 60% additional residential units (Espace Suisse, 2018) (Figs. 4.8 and 4.9).

Fig. 4.8

Map of Köniz Nessleren settlement located at the Eastern part of the City of Köniz (top), and pictures of the former (left) and newly transformed and densified housing stock (right) (Sources Geodata Canton Bern 2021/2023; own photographs)

Fig. 4.9

Map of Köniz Nessleren settlement located at the Eastern part of the City of Köniz (top), and pictures of the former (left) and newly transformed and densified housing stock (right) (Sources Geodata Canton Bern 2021/2023; own photographs)

4.3.4 The Case of Kloten City

The city of Kloten is a German-speaking city located about 10 km northeast of Zurich city center.

The municipality is part of Zurich’s agglomeration and metropolitan area (AZMA, 2020). From 1946 to 1948, Zurich-Kloten airport was built west of the village of Kloten. The city is also close to the airport motorway, which connects the town to the (inter)national highway system (City of Kloten, 2020a). Since 1980, the city’s population has increased by 27%. It is estimated that Kloten will increase by another 15% by 2040 (Glattal Region, 2020). By 2020, the “Circle Project” will open at Zurich airport, which will create around 4000 new jobs in the city. This population growth is difficult to combat within Kloten’s municipal boundaries. The city does not have any free unbuilt reserve zones left and therefore must densify via soft measures (e.g. conversion). Most of the buildings were built in the 1960s and 1970s and need modernization. In addition, the city of Kloten with residents from around 120 different nations is confronted with a very high degree of residential fluctuation. About 50% of the population leaves Kloten within five years. The main reason for this is the airport: many international residents have temporary positions and are only in the country for a short period. Rents are affordable for most residents living in Kloten; however, confronted with the situation that old housing stocks are currently being demolished and densified, many tenants struggle with social displacement because the upgrades lead to higher rents. In some city areas, a clear process of social segregation is occurring where particularly lower income groups can no longer afford housing (City of Kloten, 2019: 1–12).

4.3.4.1 Kloten Southern District

Empirical work conducted in the city of Kloten focused on the residential area at the southern edge of the city next to the municipal border to “Opfikon-Glattbrugg”. Due to the representative location at the entrance of the municipality, the city council decided to improve the urban situation in this area. It is planned that the district will transform into an attractive urban area in the next few years. Many new workplaces at Zurich Airport have been created, which is why an increasing number of residents are expected to move to the Kloten Southern district (City of Kloten, 2019). The area is comprised of around 20 plots owned by private institutional investors and individuals. The “kloten. milano” project—the settlement I investigated—was demolished and rebuilt with triple use density in 2016. The owner is an institutional investor and developer from the Zurich region. The around 80 residents living in the former settlement had to leave their apartments in 2016 as most of them could not afford the higher rents in the modernized buildings anymore (City of Kloten, 2015) (Figs. 4.10 and 4.11).

Fig. 4.10

(Source GIS Browser Canton of Zurich, 2023)

Map of Kloten Southern district

Fig. 4.11

Photographs of Kloten Southern district settlement before (top) and after (below) demolishment and total replacement construction and densification (Sources Google Streetview; own photographs)

4.4 Data Collection Methods

The empirical material of this book was conducted by the use of qualitative research methods. This was done in order to gain a detailed understanding of the governance mechanisms at play (institutional rules, actors’ strategies) leading to socially sustainable housing development (see main research questions) (Flick, 2007; Gläser & Laudel, 2010). More precisely, the three deductively developed key variables of the theoretical model—housing as a resource, institutions, and actors’ strategies—were analyzed by employing qualitative methods that facilitate gathering information of social origin (Yin, 2018). All data collection methods employed were intended to aid a better understanding of the complex relationships between housing and densification dynamics in order to answer the research questions. Specifically, the following research methods were employed: qualitative document analysis, participant observation, household surveys, semi-structured and expert interviews. The actual field research was carried out between August and September 2018 (Articles 1 and 4) and between May and October 2019 (Articles 2 and 3). A comprehensive list of all interviews is provided in Annex 1. The research process was moreover organized circularly. The phases of data collection, analysis, and interpretation were not necessarily regarded as conceptually distinct but as interconnected throughout the process (Behnke et al., 2010: 42).

4.4.1 Document and Statistical Data Analysis

Since this research is concerned with housing, the firststep of data collection before going to the field was a statistical data analysis (but qualitative in nature) focusing in particular on the socio-economic state of housing at the federal level as well as in each municipality (population dynamics, development of rents, vacancy rates, land, and housing prices, etc.). The analysis helped me to capture housing (re)development within its real-life socio-economic context and concerning potential use conflicts. Moreover, the housing situation in each city was related to the general housing situation in Switzerland (George & Bennett, 2005). This step helped me to further elaborate upon the dependent variable of the main research question (social sustainability in housing).

In a second step, I analyzed the regulatory institutions of the housing stock both at the federal, cantonal, and municipal levels (sub-question 1). This helped me to understand the institutional regime governing housing under densification pressure. Since it was impossible to review the full extent of laws and policies that constitute the institutional regime, I primarily focused on regulations and policy instruments that were considered to have the most effect on the housing stock’s sustainability. Besides housing, planning, and building laws directly impacting the extent and range of housing, these also included more indirect ways of public intervention such as environmental, monument protection, tax laws as well as property rights, contracts, and tenancy law. The aim of the content analysis was to structurally filter the documents in relation to certain topics and aspects of the problem of interest and to summarize them (Mayring, 2010).

In all four papers, I performed a broad screening of policy documents at the interface between urban densification, housing, and social sustainability issues (affordable housing, social mixing, etc.). The qualitative analysis included written sources such as government reports, legislation, strategy papers, and parliamentary debates that were primarily published within the last decade. I also incorporated newspaper articles, project documents, and “grey literature” in order to understand the characteristics of the specific formal rules in force.

4.4.2 Participant Observation

A second important source of information was provided by participatory observations (Reuber & Pfaffenbach, 2005). I employed this step in order to better understand the research context and to gain knowledge prior to the interviews in which actors’ strategies and objectives were assessed (sub-question 2). To do so, I spent a lot of time visiting the cities and densification areas selected and sought to speak to as many people as possible in order to gain various insights from residents and other stakeholders. For instance, in Zurich Brunau, I spent a considerable amount of time at the playground and in the backyard speaking to parents or elderly people who had only recently received their contract termination. A variety of people used to come to have a chat with me as they noticed that I was taking notes and documenting my impressions when visiting the place.

In Basel Schorenweg, I visited an 86-year-old female resident, who was living alone in her flat struggling to find an alternative dwelling. A nurse who helped her to cope with the situation supported her. I spoke to both several times in order to grasp valuable insights into how older people deal with densification challenges. While I was mostly just an observer on these occasions, I also participated in tenants group meetings led by the local tenants’ associations. These conservations revealed a lot about life in the densification area, about neighborhood relations or conflicts as well as investors’ and public authorities’ communication strategies with tenants.

Furthermore, I attended opening celebrations of newly finished densification projects to gather background information on how investors communicate and how their internal organizational structures work. Thereby, I also gained knowledge of how the relations between the investor, the developer, and other supplying firms of the real-estate industry such as private architecture or planning offices are managed. During my doctoral studies, I also attended a six-month program of advanced studies in urban management at the University of Zurich. In this course, I met professionals working for the private real-estate industry and learned a lot about their decision-making behavior. These gatherings granted me important insights into the discourses of economic players that they use to legitimize their actions.

During both research periods, I constantly wrote down my analytical thoughts and memos in my field book (Charmaz, 2008: 162). I noted all observations and informal conversations and tried to record as many details as possible right after the informal discussions. I wrote down specific questions for which I ought to seek out specific respondents to constantly improve my knowledge and to precisely tailor my interview questions.

4.4.3 Household Surveys

As outlined in the theory part of this book, the principal source of evidence concerning socially sustainable housing development in densification processes is considered to be people themselves, particularly those living in the areas in question (Bramley et al., 2009: 2129). With this in mind, I conducted a household survey with 412 households living in the settlements of Zurich Brunau and Basel Schoren to gain a detailed understanding of the residents’ perspectives (sub-question 2). The survey enabled me to determine the profile of the residents, their motivations, and the socio-economic challenges they are currently confronted with. The two large-scale densification areas were selected for detailed comparative analysis of households’ perceptions as they are both owned by the same institutional investor (Credit Suisse [CS]; see Article 2). Moreover, CS’ projects in Zurich and Basel were both ongoing at the time of investigation (between May and October 2019), which is why the tenants involved could be directly confronted with their decisions and actions taken. By following this project-based approach, I investigated social sustainability in housing “from the ground up, as it actually exists in local places, and as a set of evolving practices” (Krueger & Agyeman, 2005: 416).

The household survey incorporated the social sustainability indicators presented in Article 2 and included both open and multiple-choice questions. The open questions were used to gain a rich understanding of the households’ perspectives on how tenants are affected by densification plans. The multiple-choice questions were used to further underline household positions, but the analysis remained qualitative in nature. I opted for a self-completion postal and digital survey method (with one reminder) and managed to achieve a respectable 25% response rate (101 responses in total). In designing the questionnaire, I considered the existing body of literature as well as a number of national surveys covering similar topics that helped me to identify whether and how questions have been shown to work.

4.4.4 Semi-Structured and Expert Interviews

To understand the diverse strategies and the behavior of the actors involved in densification projects (sub-question 2), I employed 54 semi-structured interviews with representatives from both the public and the private sector. These included policymakers from the national to the local district level, practitioners from public ministries, and representatives of homeowners’ and tenants’ associations, housing cooperatives, neighbors, and residents (Annex 1).

Out of these, 42 were conducted as expert interviews and 12 as semi-structured interviews with residents. My intention in performing expert interviews was to gain detailed information about how specific individuals and activist groups perceive densification in relation to their particular function (Meuser & Nagel, 2009: 57). Experts interviews are particularly useful in research settings that intend to identify causal mechanisms that are to be analyzed in a more detailed manner and from a range of different perspectives (Blatter et al., 2007: 60). For example, I interviewed several politicians due to their expert knowledge and professional position in parliament or in public administration. By conducting interviews, my goal was to investigate the actors’ reasons and motivation to participate in residential densification (SQ2). All experts were chosen due to their detailed understanding and knowledge of the topic as well as based on their practical expertise related to the position they occupied within certain institutional structures.

For the interviews, I prepared thematically structured guidelines in the format of a semi-structured questionnaire. I sent the guiding questions to the interviewees in advance so that they could prepare for discussion. In contrast to standardized interviews, performing semi-structured interviews enabled me to explore the interviewees’ knowledge during the interview process in an explorative manner (Gläser & Laudel, 2010). All interviews were conducted in person and were mostly held in the offices of the respondents or alternatively at a location they chose (e.g. one politician was interviewed in a restaurant). All interviews were recorded with the permission of the respondents. In the majority of cases, interview participants were alone, and the interviews could proceed undisturbed. All interviews lasted between 60 and 90 minutes. I stopped interviewing people when no further knowledge could be gathered, or the same information was repeated by different sources.

4.5 Data Analysis Methods

The qualitative data material—either in the format of documents, surveys, or interviews—was analyzed by following general principles of qualitative content analysis (Gläser & Laudel, 2010: 46; Mayring, 2010). The three deductive variables—housing as a resource, institutions, and actors’ strategies—and the mechanisms that bind their interaction (independent variable) were identified in the text via a code-based context analysis. First, the non-written data material (audio interviews) was transcribed into text using a professional transcription service and then coded with the help of MaxQDA as the data analysis tool. The software aided in deleting or rewriting specific codes in an effective manner. The text was then analyzed along the three variables at play and related to the specific themes the interviewees raised in each of the three subsections. I however did not only focus on deductive coding. Rather I combined inductive and deductive coding and remained open to emergent themes during the process of data analysis (Charmaz, 2008; Emerson et al., 1995; Glaser & Strauss, 1967). In essence, I coded my data using thematic codes based on my research questions and theoretical concepts as well as more analytical codes that inductively emerged from the data.

4.6 Positionality, Reflexivity, and Validity of the Data

The variety of data collection methods as well as the time spent in the municipalities and densification areas strengthened the validity and reliability of the results. Risks of selective data acquisition were reduced by triangulating different qualitative methods. However, every method applied has its own limitations that I would like to briefly reflect on to arrange the results within an appropriate framework.

The questionnaire conducted with tenants is based on the self-assessment of the respondents under the basic assumption that participants respond to the surveys according to their best knowledge and based on subjective perspectives. The qualitative statements, however, were not verified or compared on a more general basis. Even though the variables incorporated in the questionnaire were justified by referring to theory, there is still a possibility that relevant data could not be effectively captured. The statements made in the questionnaire helped to interpret some of the results; however, a closer examination (e.g. in-depth expert interviews or broader statistical analyses) is imperative for more valid derivations.

When performing interviews, the validity of the data was increased by sending the questions to the participants in advance so that they could prepare for the task. In addition, training was carried out with the participants at the beginning of each interview in order to make the data collection process more transparent. I also paid particular attention to data documentation (e.g. in transcription, and field notes) to make each step of data collection explicit and replicable (Gläser & Laudel, 2010: 193). To guarantee data protection, I moreover asked all residents interviewed to sign a document for ethical approval to ensure that the data collected in their homes can—in an anonymous way—be used for publication.

Finally, my identity as a researcher played a key role in the data collection process and the interactions with various stakeholders in the field. I noticed this in particular in discussions with institutional investors or politicians who, at the beginning, were very skeptical towards land policy research since they obviously perceived it as a left-wing policy. While trying to analyze densification from a social science perspective, I became aware that I am simultaneously an actor. Urban science itself is a social area with its own power games. My scientific knowledge is always subject to strong uncertainty, positionality, but also subjectivity. Since I identify myself as a critical human geographer, it was very important for me to explain the background of my work in detail before gathering data in order to create mutual trust and an open atmosphere. I made my research objectives very clear from the start and always explained my interests in analyzing (not judging) densification processes from a human geography and political ecology perspective, which includes a focus on power games.

Furthermore, the sensitivity to the tenants’ housing situation was difficult to manage in many ways. It was never my intention to encroach upon their privacy, but to collect valuable insights I sometimes had to ask very personal questions, for example, concerning their future housing options even though they only recently received contract termination. In these situations, it was my impression, however, that my age or gender (or both) helped to establish a connection with them. They considered me more of a friend than a pure researcher and were very open-minded to tell me about their current living situation. After all, keeping a research diary was an important part of reflecting on my positionality and the way it affected my interactions with different stakeholders involved in the process.