The Creeping Gentrification of a Street: The Case of the Historic Oval-Shaped Kościelna Street in Poznań

Abstract

The subject of the research is the attractive Kościelna Street connecting two prestigious districts of the city of Poznań (Jeżyce and Sołacz). The oval ring layout of the street with its characteristic green separation strip sets the tone for the entire district. The urban layout, preserved for almost 300 years, is tied to its pioneers—settlers brought from Bamberg (Upper Franconia, Bavaria). The problems of maintaining the historical identity of the place and its inhabitants as well as the identity of the architecture (transformation from farmstead to frontage layout) are highlighted. The phenomenon of gentrification is the background to the deliberations. A chronicle of events over three centuries allows it to be described as creeping. Nevertheless, three types of gentrification have been examined: economic, social and symbolic (cultural). Research methods in the context of the multidisciplinary nature of the issue, emerging dilemmas and an overview of street attractiveness research are discussed. A method based on the Net Promoter Score has been used as an aid to determine the attractiveness of an architectural structure. The importance of social and symbolic aspects has been pointed out so that gentrification does not become rapacious.

1. Introduction

It happens before our eyes, sometimes we do not see it (sometimes we refuse to notice it). It is a phenomenon, a process. We usually notice it after a while (aftermath of events). It is gentrification, which is one of the main processes mainly in contemporary cities and, at the same time, one of the challenges not only for city authorities, architects, urban planners and designers of public spaces but also for sociologists, economists, demographers, historians and ethnographers. Multidisciplinarity is a feature of gentrification. Research, dissemination of the essence of this process, the body of work and its advantages and disadvantages are needed.

It was first defined only in the second half of the 20th century. It generally boils down to a process of changing the character of a given area of the city, increasing property prices and improving the quality of life of its residents. Most often, gentrification takes place in neglected districts, streets that have considerable economic potential. Unfortunately, this process is accompanied by, among other things, displacement (sometimes drastic), an increase in the cost of living, a blurring of cultural identities and even potential neglect of the architecture. The considerations presented in this article take into account the newer aspects of gentrification, i.e., economic, social and symbolic (cultural).

The physical subject of the research is the district of Jeżyce, and within it, the characteristic Kościelna (Church) Street, which connects two contrasting yet prestigious and important districts: the dynamic Jeżyce and the quiet, gentle and elegant Sołacz. Both districts are located in the western and north-western part of Poznań (Poland), a city halfway between Warsaw and Berlin. This situation is illustrated in Figure 1. Kościelna Street is an important element of the former urban layout of the village of Jeżyce. It also has an interesting history (not only urban but also settlement) and has a specific historical identity. A distinctive feature among the streets of Poznań is the oval layout with a characteristic green separation strip. The urban layout has been preserved for three centuries. At present, despite the green separation strip, the street does not fulfil the conditions of a pedestrian avenue as it has mainly transit functions.

The Jeżyce district, where Kościelna Street is located, ranks highly in the architectural brand research. Among the seven characteristics studied, uniqueness stands out clearly: 100 points for Jeżyce, less for other districts, e.g., Sołacz 75.8 and Wilda 67.2 [1]. This is one of the factors creating the attractiveness of a street. The uniqueness of Kościelna Street also lies in its turbulent history. The resulting historical identity underpins the architectural identity: this includes the transformation of its homestead character into two frontages. An important role was played by a group of displaced persons from Bamberg (Bavaria) who were brought to the then poor Wielkopolska region. Their assimilation, way of life and work set the tone for the cultural identity of the place.

These two spheres of content in the article, i.e., gentrification and Kościelna Street, are linked by research. Multidisciplinarity has an impact on research. More often than not, the hard-won data are static, while the gentrification process itself is dynamic. There is no uniform measure for social or architectural issues. From a scientific point of view, research cannot be replicated by means of an experiment, as gentrification is a one-off process.

The article focuses on the research of the attractiveness of a street, gives a brief overview of research methods in this area and attempts to research attractiveness using the Net Promoter Score (a passer-by may have a different rating than an architect). Finally, the importance of social issues (e.g., stratification, bottom-up social initiatives) is highlighted.

The introduction to our considerations is Figure 2. It presents the most relevant dates—formally, the earliest is 1729, but the chronicle of the street’s gentrification begins with the Northern War (early 18th century) and ends with student and community action in 2024. It also looks to future neighbours beyond the existing Kościelna Street frontages. Figure 2 illustrates the process of gentrification with characteristic events and some disturbances that determine the creeping process, its slowing down and economic and political turmoil (i.e., partition of Poland, long Prussian rule, communist rule). These events form the outline of the article.

The article refers to critical remarks about revitalisations and attempts to gentrify districts in Poznań (Ciesiółka [2,3,4], Bardzińska-Bonenberg [5], Pawlicka [6], Jachowska [7] and Głaz [8,9]). Relevant references are provided for each section. The dilemmas of gentrification are presented in the article primarily in the context of Kościelna Street and the Jeżyce district.

2. Background: The Phenomenon of Gentrification

The phenomenon known as gentrification was defined and consolidated back in the late 20th century. The original term denoted a form of social exchange process in central parts of the city; it is also known as classic gentrification. This was due to the increase in land and building prices and the consequence was class exchange, i.e., the displacement (sometimes violent) of the poorer population and the influx of the richer middle class—see Glass [10], Hamnett [11] and even Huxtable’s [12] sarcastic term. Such a process of transforming one or more city districts from a public (social) space to a totally commercialised and purely market-controlled area is often explicitly called embourgeoisement. This means the transformation of districts, e.g., hitherto working-class or so-called poorer districts, into districts dominated by residents from wealthier social classes.

Later in the research, the scope of gentrification evolved into three ‘pillars’ (types): economic gentrification, social gentrification and symbolic (cultural) gentrification, which, in combination or separately, characterise and evaluate the place under research (e.g., city, district, street) in a fairly holistic way—Karwińska [13] and Główczyński [14]. This means that demographics, living conditions, even social composition, civic initiatives, etc., must be taken into account in addition to architecture and urban planning.

Urban and architectural problems as well as investment processes, modernisation, called revitalisation, increasing the attractiveness of the place, are the basic features of economic gentrification. Changes in the social composition of the community living in an area, social stratification and livelihood issues are characteristics of social gentrification, sometimes referred to as final gentrification. Symbolic gentrification, also called cultural gentrification, is above all the formation of the inhabitants’ awareness, grassroots social initiatives, self-organisation and education; it is also the creation of an aura of uniqueness and later prestige associated with a district or street.

There are many examples of gentrification, and no example is the same, which contributes to the diversity of the positive and negative aspects of gentrification—cf., e.g., [15,16,17]. Gentrification is based on three ‘pillars’. The boundaries are blurred, but if one is dominant, e.g., the social pillar, and is based on students, then we have studentification, and if it is based on creative young people and business representatives, then we have youthification (cf. Grand Canal Docks district in Dublin). This is pointed out by Revington et al. [18], Zasina and Jakubiak [19], Astore and Tricarico [20] among others. But, if it is based on tourism, as in Seville, Barcelona, Venice and Krakow, then touristification (where there is a preponderance of rental housing) comes to light [21,22,23]. The changes that take place in the rural community under the influence of the onslaught of the city constitute the phenomenon and process of rural gentrification [24]. However, this is not the phenomenon of urban sprawl.

It is difficult to attribute elements of empathy to gentrification: we have often seen rapacious gentrification in countries on many continents, e.g., the abolition of single-storey buildings in favour of skyscrapers, the elimination of ghettos (e.g., black neighbourhoods). In the background of the deliberations, the moral aspect lingers: It is worth reflecting and asking whether colonialism had gentrification characteristics—cf. [25,26,27].

In these last few examples, gentrification is a process in which an area (e.g., a district) abruptly changes its character; moreover, it has pejorative connotations. But, there are gentrifications with positive connotations, received with applause. Perhaps the most prominent examples are the Grand Canal Docks district (along with Grand Canal Street) in Dublin and Camden Town along with Camden High Street in London. Both streets were immediately given the nicknames ‘Smile of the Street’, and the media reported the presence of the ‘Colourful Crowd’. Is it possible for a street in Poznań in the district of Jeżyce to achieve the laurel ‘Smile of the Street’? The gentrification, the history and the identity of this street are objects of research. The contemporary problems of this street are also interesting. Due to the (oval) urban layout of the street, the assimilation of the settlement population, the architectural style of the homesteads and the preservation of cultural continuity, it is possible to determine that what we are dealing with here is creeping gentrification, constantly on the move and with prospects.

The term creeping gentrification is a new term, introduced by the author to emphasise, among other things, the role of the immigrant/incoming population, the specificity of the historical identity of a place. At the same time, creeping gentrification fits into the three pillars of gentrification mentioned above (economic, social and symbolic). The fate of this gentrification is presented later in the article.

Thus, creeping gentrification is not only creeping rents, but it is the events of three centuries, the preservation of the urban layout, it is the economic and political turmoil, the survival of partitions, wars and the command/planned economy, it is the assimilation of the settlement population, the changing attitude towards them, the preservation of cultural continuity, it is the historical identity, the changes from homestead development to frontage development, the incorporation of the village into the city, it is the creeping demographic changes, it is the awakening of the society and even the exclusion from the surroundings. It is a gradual transition through different formations of economy: from market fundamentalism to ordoliberalism.

3. Study: The Power of Place

3.1. The Historical Identity of the Place

Historical background plays an extremely important (if not the most prominent) role in the gentrification of Kościelna Street. In the case of this street, gentrification starts from an almost deserted place in contrast to other known cases of gentrification. It was history that dictated the course and outcome of gentrification and largely determined the fortunes of the people and the architecture. The weight of historical identity is part of the appeal of this street.

At the beginning of the 18th century, after numerous natural disasters plaguing the territories of this part of Poland, the Swedish occupation, the devastating Third Northern War (1700–1721, a war of Denmark, Russia, Saxony, Prussia, Hanover and Poland vs. Sweden) and the plague epidemic of 1708–1710, the settlements near Poznań were almost completely destroyed and depopulated. One of the main problems became the repopulation of the ravaged villages and manor estates. At the invitation of the authorities of the city of Poznań, between 1719 and 1753, farmers came in several waves (mainly from the Bamberg—the Bavaria region). The first colonists arrived in the village of Jeżyce in 1729. The second wave came 20 years later. Each settler was obliged to present a document confirming that he or she was of the Roman Catholic faith (in accordance with an injunction issued by King August II the Strong in 1710 concerning all foreigners settling in Poland). The new settlers enjoyed a convenient legal framework by switching from serfdom to a rent economy. They were temporarily exempt from taxes. They were also given timber for house construction and grain for sowing [28,29]. The assimilation of the Bambers began, and wealth and building development began. Paradoxically, this gave rise to the creeping gentrification of the village of Jeżyce. The community of faith was the most important platform for the rapid Polonisation of the Bambers. The second factor that contributed to the assimilation of the Bambrian group into the Polish community was the school.

In the oldest cartographic accounts, Jeżyce (today’s Kościelna, in German records as Dorf Jerzyce) is an oval village with two ponds and a mill inside [30]. Homesteads were mainly built around the oval, with gardens, orchards and fields at the back. Some homesteads were built around two side roads from Kościelna Street to the town of Poznań. This urban layout is already visible on the Prussian plan of around 1841. Its replica is shown in Figure 3. The colonists became rich quickly thanks to their industriousness; so, they built new buildings, mainly along the Poznań–Berlin thoroughfare (today’s Dąbrowskiego Street) and south of it.

In 1793, Wielkopolska was occupied by the Prussian army (this was the Second Partition of Poland), and between 1848 and 1920 Provinz Posen formally existed. Poznań was given the status of a fortified city, which influenced the architecture of the houses outside the walls. Strict building restrictions were in force in the fortified areas, hence only wooden or half-timbered buildings suitable for immediate demolition in the event of an enemy attack were allowed there. It was not until the strict fortress restrictions were lifted in 1889 that construction activity in the then already very large village of Jeżyce was intensified.

Elements of the natural systems ceased to serve their previous function, and efforts were made to build on them. However, the oval layout area in Kościelna Street was left free of development, and only the water system was removed [31]. Between 1807 and 1899, a church dedicated to St Florian was built, and the name of the street was changed from Jeżyce to Kościelna (Church) Street. During this period, Bamberg settlers were keen to build half-timbered houses. There was a process of differentiation in the size of buildings, which was linked to the natural process of differentiation in the wealth of society. Forms, details and proportions were differentiated. This gave the buildings a distinctive appearance and created the atmosphere of the space. In the Jeżyce district, you can still see many of these buildings, which stand out for their architecture.

A landmark date in the transformation of today’s Jeżyce was 1900, when it was incorporated into the city of Poznań. A dynamic building and economic development took place in this part of Poznań. The urban development also included Kościelna Street, and the area to the west of the street was designated as an industrial area.

Unfortunately, there were two periods of stagnation in the development of the Jeżyce district. The period after the Second World War was marked by, among other things, partial but sporadic mandatory lodging of additional residents. Above all, the authorities did not like German-sounding names. The systemic (economic and political) changes in Poland after 1990 were also critically reflected—there was a concern of partial social degradation of the entire Jeżyce district. Previously creeping rents became predatory due to escalation, but this did not result in a sudden exodus of the settled population. The attractiveness of the street remained constantly in the background. Over time, new developers appeared (21st century). Discussions and efforts to revitalise this part of Poznań intensified. A social organisation called Initiative:Open was established, focused on revitalisation.

3.2. From Homestead Development to Frontage Development

Kościelna Street is unique in Poznań. Its 300-year-old shape is a remnant of the former oval-layout village of Jeżyce. The name of this village was taken over by the whole district, which already had orthogonal buildings with full infrastructure and was incorporated into Poznań in 1900. The district of Jeżyce is today one of the most popular ones.

Its shape is oval, somewhat resembling a municipal boulevard. Between the carriageways, there is a characteristic green separation strip, about 30–40 m wide, once homogeneous, obviously green and with ponds arranged in the middle; the Saganka stream (now channelised) used to flow there. Today, the strip is largely degraded but partly wooded. For several decades, the separation strip was divided into two parts because of the petrol station located there. Fortunately, as part of the envisaged revitalisation of this part of the district, the station was dismantled in the summer of 2024. Remediation of the land after the petroleum substances is still required. The matters of the car park (fenced), transformer shed and dog run remain to be resolved. The lane is not currently a walking lane.

The length of the entire street is 650 m, i.e., from Dąbrowskiego Street (former Berliner Tract) to the viaduct (Grudzieniec Street) The slope of the terrain along the street is clearly visible. Level difference: from 79.8 m a.s.l. to 65.6 m a.s.l. along approximately 15 m. The length of the separation lane is 429 m (in a straight line), and differences in elevation are approx. 9 m. Its extension to the north is Nad Wierzbakiem Street, which is part of the Sołacz district.

Over time, the homestead buildings began to be replaced by residential buildings (tenement houses). This process dominated the entire 20th century. Until the end of the 20th century, the old suburban (even rural) atmosphere could still be felt on Kościelna Street [8]. Since then, the street has been encased more and more densely with residential development, with neo-modern, less historic forms. These 20th-century buildings, together with the new ones, create frontages that did not previously exist. Both frontages are illustrated in Figure 4 and Figure 5.

The western frontage is the best consolidated. It begins in the upper part with St. Florian’s Church, the middle part is clearly a neo-modern form, followed by buildings with an attempt to incorporate historical forms, including half-timbered walls. The pearl in this frontage (in its lower part) is a fragment of the urban–architectural complex—the buildings of the Bamber Homestead (43 Kościelna Street). Due to their significance for the historical and cultural heritage of Poznań and Wielkopolska, these buildings have been protected. The historic buildings date from the 1870s. Their renovation and adaptation into a hotel and restaurant were completed in 2000. The traditional look of the homestead was preserved, and the interiors were arranged according to old photographs, using memorabilia of the Poznań Bambers. A view and sketch of the homestead are shown in Figure 6. From the entrance gate on the right were the manor buildings and servants’ quarters, and the cobbled courtyard ended with the coach house where the restaurant is situated today. On the left are the livestock buildings, now converted into rented office space.

The eastern frontage (Figure 5) is largely in need of regeneration. It begins with a round-shaped commercial building from the late 1970s/early 1980s, poorly reflecting the spirit of a street with historical tradition. In the middle section of the front is a squalid area with a hot dog stall, an old car junkyard and a scrap metal collection point. It was a fragment of this area that students of Poznań University of Technology looked at as part of their thesis. The results of their investigations and research using the NPS method are presented in the following sections.

3.3. Revitalisation Attempts and Student Participation

There have been attempts to heal the space of the oval street from the public and the estate councillors. Concepts have changed, and authorities have changed. Serious efforts to revitalise the attractive street began in 2013 with a discussion arranged by Initiative: Open. It was agreed that it was not to be a new market in Kościelna Street but a frontage connecting Sołacki Park with the large Jeżycki Market [32]. The involvement of students from the architectural faculties of two Poznań universities—the Magdalena Abakanowicz University of Arts in Poznań and the Poznań University of Technology—is worth mentioning here.

In the first case, the project entailed merging this space and better arranging the separation lane. Earlier critical remarks by city councillors led the city, together with the University of Arts, to launch a competition for new ideas for Kościelna Street. The aim of the competition was to find the best ideas for developing an accessible and multifunctional public space, serving both the local Jeżyce community and other residents of Poznań. The participants of the competition had to take into account, among other things, the traffic and natural conditions of the street, conservation recommendations, the provisions of the local spatial development plan and the needs of the inhabitants. It was important to refer to the history of Kościelna Street, to emphasise its specificity as well as the coherence and attractiveness of the proposed solutions. The creation of the project required extensive analysis by the students, which included field work [33].

Seventeen entries were submitted to the competition, and the city authorities were reverent about the results. The winning project envisaged that it would not be another avenue that we could primarily, and only, walk along, but a place to stop at. Figure 7 presents one of the visualisations.

The students’ proposals were very interesting but proved impossible to implement at the design documentation stage. Among other things, water retention issues were not resolved. The new project will incorporate solutions to increase the natural water retention capacity of the ground. According to the guidelines, a hybrid retention system is to be designed. The city announced (2023) a tender for the documentation for the development of Kościelna Street, and the designer is to be selected in the tender (with, among other things, the criterion of price), which was met with criticism from Poznań architects [8].

The students of the Faculty of Architecture at Poznań University of Technology were given a task of developing an undeveloped plot of land on the eastern frontage (38 Kościelna Street). Once again, the students sensed a favourable atmosphere among residents and local councillors during their design work. Thus, the students completed their bachelor’s thesis—based on the feasible development conditions for an investment consisting of the construction of one of the following buildings (optional): an office building, a pension or an apartment building, all with services on the ground floor, in a frontage development, to be built on plots 118 and 154. The zoning decision included, among other aspects, the construction line, the area of the application site (1319 m²), the built-up area ratio (up to 51%), the biologically active area ratio (minimum 25%), the roof geometry and the cornice line of the building. On the other hand, the number of floors and underground levels was three to five and one to two, respectively. There were two editions of the themes on the same plot (2019, 2020).

In both editions, the form of each building was treated as a dialogue with its surroundings. It was largely possible to refer to the divisions created by the window openings, the vertical composition of the façades of neighbouring buildings. In some cases, it was possible to retain architectural accents (a truncated corner or even a bay window) that allude to the 19th-century building tradition of the area. Nevertheless, each project was an attempt to create a contemporary form that would fit into the urban frontage. The street form with services concentrated in the ground floors of the buildings strongly relates to the tradition of the street, which can play an important role in shaping the community life of the district. In several projects, the front wall is articulated by rhythmically repeating vertical windows. The verticality is also emphasised by a ‘crack’ cutting through the façade at the point of the staircase, which also allows more light into the space. The separation of the ground floor has also been achieved by using a different material.

Examples of 14 projects (selected from dozens) are presented in Figure 8. These provide material for analysis using the NPS index (see Section 5 for a description). The results are presented in Figure 9 and Figure 10. Among other things, attention was paid to A/V shape factor in the projects. The most favourable A/V value has the building in project#7 (A/V = 0.14), the most unfavourable is the building in project#14 (A/V = 0.519).

Similarly, project#7 has the largest floor area (4408 m²) and project #14 the smallest (3138 m²). Furthermore, project #14 has proved to be the most controversial. The projects were discussed by the faculty, and the graduates had the satisfaction of being prepared for their profession and the knowledge they gained from their historical and architectural identity. The sublime projects were further examined for architectural attractiveness, creating added value for Kościelna Street, also bringing economic and marketing benefits.

4. Gentrification Research

4.1. Methods and Dilemmas

The issue of gentrification as a phenomenon is itself very complex—suffice it to mention the three pillars of issues, from regeneration to social issues. This is reflected in the research methods and considerable simplifications that have to be made. An example of this is the well-known UHC professional research group on gentrification at Drexel University, which focuses (separately) on three research themes: on demographics; on changes in property values; and on residents’ access to health care, street appearance and reinvestment—according to Hirsch and Schinasi [34].

From the already extensive experience of research in this area, methods depend on the nature of the data and how they are obtained [35]. This makes it difficult to identify the relationships between the different pillars (types) of gentrification. For example, how to determine the climate of a place or its prestige in symbolic gentrification and link it to a change in social composition. Gentrification does not have an objective outcome nor is it possible to test this phenomenon with a reproducible experiment. The multidisciplinary nature of gentrification requires the involvement of researchers from a variety of disciplines, resulting in a multiplicity of research approaches. The lack of uniform definitions is one of the reasons why transformation processes are confused with reurbanisation (the migration of people back to an area that has been abandoned in the past) and the gentrification process. This was (and sometimes still is) evident in post-socialist cities, where the gentrification process was less important. This is signalled by, among others, Grzeszczak [35], Grabkowska [36] and Jakóbczyk-Gryszkiewicz et al. [37]. A review of the Polish and foreign literature is provided by Główczyński [14]. The use of available quantitative data in research is pointed out by Anielska [22] and also by Jakóbczyk-Gryszkiewicz [38] and earlier by Ley [39] and Kolko [40]. Anielska [22] is based on three groups of indicators: for the historic/tourist city of Kraków, the dominant indicator is a decrease or increase in crime. Other authors include the following as key factors influencing gentrification in specific districts: location (including the surrounding area), housing stock and demographic stock. Several indicators are identified for each factor.

Gentrifying neighbourhoods are most often described in the English language literature. These are generally urban units and segregated districts. The gentrification of a street or a single building is rarely discussed. Due to the strong historical and cultural values and attractiveness of Kościelna Street, we will limit our further discussion to the gentrification of the street.

4.2. Street Attractiveness Research in the Context of Kościelna Street

In the search for an assessment of the attractiveness of a street, more and less appropriate methods and instruments are also encountered, and there are various criteria. Here are some characteristic research issues. We start with the potential of a street view.

Street views and window views can enable restorativeness, improving the wellbeing of residents in a densely populated urban environment. Koprivec et al. [41] applied Kaplan’s Attention Restoration Theory (ART). This method of assessing urban views can be enhanced by Lynch’s theory of designing urban space. The authors recommend that this complex approach should be used at an early stage of design. This method is based on surveys but is far removed from eye tracking.

Interesting results can be obtained by studying architecture as a brand of urban space. Here, it is important to define an architectural brand identity and build a brand template for a given agglomeration, for districts and streets, in order to be able to compare brand characteristics and attributes of architectural forms that build the brand. For comparison purposes, the results are reduced to relative values. Research requires queries. The poor value of architecture occurs when there is a discrepancy between the identity and the visual identity of the brand. Research on the architectural brand has been conducted at Poznań University of Technology since 2003. The results have attracted the interest of the city authorities [1,42].

There is a close relationship between the thematic profiling of a street and its commercial attractiveness. Research on the creation of thematic shopping streets and the commercial attractiveness of retail and service establishments and their impact on urban activation in downtown Poznań is presented by Giedrowicz [43]. In this case, parametric modelling proved useful. Among the (now traditional) analytical tools used are the Likert scale and the Shannon–Wiener, Pearson, Kolmogorov–Smirnov indices and tests. There is also an attempt to use the Grasshopper calculation and parametric modelling software, an overlay of Rhinoceros 5.

Attractive streetscape features are one of the reasons why local residents prefer pleasant and comfortable routes to exclusively shorter ones. Interesting Japanese research in this area is presented by Capitanio [44]. This type of research question is methodologically complex, but Space Syntax theory can be used. The author used ‘Rhino UNA toolbox’ software developed by the City Form Lab at MIT. This software is dedicated to architects and planners.

In general, urban analysis based on Space Syntax theory makes it possible to demonstrate fundamental structural differences between districts and to determine the influence of urban forms on the spatial merits of different areas of the city [45,46]. An overview of the use of Space Syntax theory in sustainable development using the PRISMA method in the relationship of urban architecture with the user stream is presented in [47].

Perhaps artificial intelligence (AI) will soon be a good instrument. A successful attempt to use AI for the measurement of urban morphology, including urban shape, built density from a pedestrian perspective and is presented by Choi et al. [48].

Hybrid combinations of specialised software with Geographic Information System (GIS) are effective. Thus, the analysis of quantitative data extracted from government websites and qualitative data obtained from surveys was visualised on GIS-generated maps, as presented by Orellana-Alvear and Calle-Jimenez [49]. Open source ArcGIS 10.8 software was used for the case research analysis.

Economic potential (the occupations of residents and their income levels, the local labour market, the level and type of entrepreneurship, the inflow of foreign capital and the state of the environment) is also an important dimension of gentrification. In this context, the Generalised Distance Measure (GDM) is very helpful. This refers to the calculation of a synthetic measure based on the research of the distance to a benchmark, i.e., an object with the desired values of the input variables. Examples of the application of the research for the Poznań agglomeration are presented in the paper by Szymkowiak and Roszka [50].

Attractive architecture as the capital of a city creates added value for the area, bringing economic and marketing benefits. Research in this area in Poznań—based on questionnaires—was conducted by Pawlicka [6]. The questionnaire contained questions with rankings. The survey was of an environmental nature, i.e., directly on the street in question. The economic value of the area was assessed before and after the investment. According to the respondents, the economic value of the area will increase after the project, which is considered attractive to observers. In addition, facilities of high aesthetic value encourage businesses to locate both in the building and in the immediate area. However, this is a potential source of accelerating gentrification.

Micek and Wachowiak [51] present research on the quality of public spaces in the revitalisation area—expressed by a qualitative evaluation index, which represents the proportion (%) of the features of a given space that are evaluated negatively or indifferently. The research was conducted for 63 types of public spaces in Poznań. To everyone’s surprise, the squares in the area of Kościelna Street received a significant (negative) rating of 87.5%, which alarmed residents, the housing estate committee, councillors and even students of architecture faculties in Poznań.

Today, it is difficult to analyse all the components of gentrification without taking empathy into account. This applies in particular to displacement, migration, the social cross-section of residents, social initiatives, in the context of the architecture of a place, its prestige and attractiveness. At the very least, it is about the ability to understand not only the architecture, but also the feelings and needs—one’s own and those of others. One method of measuring Personal Empathy is presented by Uchnast [52]. It is worth including this approach in future gentrification research. Close to this issue in relation to Poznań streets is the work on constructing emotional maps of urbanised space, cf. [53].

Less well known in gentrification, popular in marketing, is the evaluation method developed by Reichheld [54] and using an index called Net Promoter Score (NPS). It is considered to be a recommendation index. It is helpful in testing usability and determining attitudes towards an art, a product, an institution, etc. It is fully recommended by The American Customer Satisfaction Index (ASCI), cf. Fornell [55]. We will use this method in assessing the attractiveness of the design solutions of the students of Poznań University of Technology.

5. Research of Project Attractiveness Using the Net Promoter Score

5.1. Assumptions and Conditions of the Research

The method based on the NPS index has not yet been applied to the evaluation and recommendation of architectural works. The main indicator used in the research is the percentage of net promoters, i.e., the percentage of people willing to recommend a work, according to Equation (1):

$$\mathrm{N}\mathrm{P}\mathrm{S}=\left(\% \mathrm{o}\mathrm{f} \mathrm{P}\mathrm{R}\mathrm{O}\mathrm{M}\mathrm{O}\mathrm{T}\mathrm{E}\mathrm{R}\mathrm{S}-\% \mathrm{o}\mathrm{f} \mathrm{D}\mathrm{E}\mathrm{T}\mathrm{R}\mathrm{A}\mathrm{C}\mathrm{T}\mathrm{O}\mathrm{R}\mathrm{S}\right)·100$$

(1)

When conducting research, respondents (e.g., potential users) are divided into three groups: promoters, neutrals (passives) and detractors. The response scale ranges from 0 to 10, where 0 means zero probability of recommendation and 10 means a confident recommendation by the respondent. Scores of 9–10 identify so-called promoters, 7–8 identify passives, while 0–6 indicate detractors; this being an ordinal scale, no averages can be drawn.

The survey was conducted by displaying boards with visualisations of the future buildings, explaining the purpose of the survey, holding a short discussion and encouraging people to take part in the survey and answer the question using the NPS method. Visualisations of 14 buildings were presented to passers-by. Two warm days in October (2022) were conducive to a research of an environmental nature: the survey site was located on the eastern side of the frontage, in front of the site of the future building, almost opposite the still-existing petrol station. The number of interviewees (though potential respondents) was reduced to 91. Workers at the construction site of the (then) new (chain) supermarket, which was being built outside the eastern frontage, workers at the petrol station (which was to be closed) and drivers who filled up at the petrol station were excluded from the research. Responses from hesitant (undecided) respondents were discarded, mainly incomplete and arrogant responses. Responses from 21 people qualified for further analysis; this is a relatively large number for an NPS survey [56,57,58,59,60,61].

The age of the respondents was over 20 years. Older people made up less than 30% of the respondents (six people), but they were the most insightful, with the oldest respondent being 73 years old. Women respondent ages ranged from 30 to 55 years. Responses from 11 women and 10 men were included. All of them had at least a secondary education. Among the women, four were residents of this street and seven from the Jeżyce district. Among the men, three were residents of Kościelna Street and seven were from other districts of Poznań. There were no people just taking a walk, as the green belt of the oval street chapter is under reconstruction. Surprisingly, none of the respondents were related to the Bambergs.

Analysis of responses from 21 respondents yielded 294 ratings.

5.2. Results

The responses are summarised in Figure 9. The transformations of the responses according to Equation (1) are shown in Figure 10. Responses that could not be included in the NPS method (score range 7–8) are indicated by a dashed line. The least favourable score was given to project#3 (−52 points), the highest to project#14 (+38). Project#14 proved to be the most eccentric design: this is evidenced by the appearance of local maximum and global maximum in the responses, i.e., for scores of two (negative) and nine (positive). A total of three projects were scored negatively, and three projects appeared equal with 33 points each. The higher the NPS value, the more dominant the group among respondents are promoters. The results shown in Figure 9 and Figure 10 are ratings of the attractiveness of individual building designs made by residents and passers-by. Their ratings do not necessarily match those of the architects. The method offers knowledge that reduces the so-called purchase risk and thus increases sales. These results, even in this form, can be used by developers and real estate agents to determine the marketability of a building. For an architecture studio, it can be a harbinger that there are not only architects but also prosumers in the market. The NPS supports the gentrification assessment of a street or a district.

The NPS is only an ad hoc tool. It is not a scientific method. NPS is an indicator, highlighting the role of promoters. This indicator can only support the gentrification assessment of a street or a neighbourhood. It is useful in evaluating products and employees in determining attitudes towards an object (e.g., art). In our case, it has been used in assessing the attractiveness of students’ design solutions—towards their awareness and their knowledge of the reception of their future achievements. This is the first attempt to apply the NPS to the evaluation of design solutions in architecture. As indicated in Section 4.2, there is not yet an adequate method developed to assess the attractiveness of a street, let alone in terms of gentrification.

6. Economic, Social and Symbolic Complements to Gentrification

A full analysis of gentrification requires information on the three pillars mentioned. Valuable information and statistics are provided by publications and reports produced by specialist real estate companies. A CEO company signals surprising changes in Jeżyce [62]. In the District Ranking, the national company Otodom reported that Jeżyce is in the top three districts in as many as three categories, in terms of access to health services, tourist destinations and also events [63]. Jeżyce is one of the most searched parts of the city in the whole of Poznań, with the number of online searches increasing annually by around 23% [64].

The price per square metre of an apartment to be bought in Jeżyce continues to creep upwards. If the average price in the whole of Poznań increases by less than 6%, in the area of Kościelna Street it increases by an additional 5% [65,66,67].

The average prices of flats per m² (2024, second quarter) for the district of Jeżyce amounted to PLN 12,167 with the average for Poznań amounting to PLN 11,692. The annual price change for Jeżyce is +20.0%, while for the most expensive (noble) district of Sołacz, this increase is 17.1%. For the other districts, the increase is much lower or even negative (Antoninek: −2.6%).

It sounds a little ironic, but one of the basic conditions for the gentrification of Kościelna Street and its surroundings (rising prices) has been met. Despite these prices, there are people who want to move to Jeżyce and can afford it. Will Jeżyce fall victim to its own success?

The demographic resource is the core of social considerations. The problem lies in migration, especially in the population decline in the city of Poznań. According to data from 2016—despite the overall population decline in Poznań—the district of Jeżyce has maintained its current population level. Compared to 1990, there was only a minimal decrease in population there (by 0.3%). The largest population decrease was noted in the districts of Grunwald (15.2%) and Wilda (12.3%). In contrast, the report ‘Population forecast for the Jeżyce estate 2015–2050’ (see [68,69]) predicts a linear decline in the number of residents from 24,497 (in 2015) to 17,048 (in 2050). There will be a creeping increase in the 65+ age group, i.e., from 3815 to 5943, respectively. These projections may be disrupted as Kościelna Street itself will be surrounded by new housing estates; on the western side (a post-industrial area), a large housing estate for 7000–8000 inhabitants is envisaged. On the eastern side (also outside the frontage line), a complex with 120 apartments will be built.

This is what existing residents fear; there are already signs of concern about this new development (see, for example, [8]), for the social structure, the number of space users and communication will change. The old residents of Kościelna Street also signal the exclusion of the newly built housing estates in the Jeżyce district from surroundings in terms of architecture. If some of the buildings constructed in the area of Kościelna Street visually refer to the architecture of the ‘old’ Jeżyce, the newer apartment buildings do not blend in at all with the 19th- and 20th-century buildings [7]. Here, we see a serious bow to Poznań architects.

A positive aspect of comparing the values for 2013 and 2015 is the reversal of unfavourable migration trends in Jeżyce, as this unit changed its character from emigration to immigration during the period under review. The age structure of the population living in the study area is changing very slowly. The age dependency ratio is consistently high, standing at 33.4 in 2015 and at 32% in 2022 (Instytut Poznański [70]). According to these data, the level of education is higher than the average for Poznań (the area subject to revitalisation plans), while it is lower with respect to crime, poverty and unemployment [71,72].

Shaping the awareness of residents is the content of symbolic gentrification. Initiative:Open plays an important role in this area, and it was from Initiative:Open that the efforts to revitalise the attractive street began in 2013. They were guided by the idea that if revitalisation is supported by the local government, the residents’ association and institutions, if the process is controlled, it can mitigate the effects of wild, violent gentrification. On the initiative of the local councillors and the organisation Initiative:Open, an architectural competition was held for students. The residents themselves protested (successfully) against the construction of tall buildings directly behind the street frontage. Residents are also concerned about the increasing number of rented flats: tenants rarely take part in social life. Perhaps a new social composition will emerge after the construction of a large new housing estate on the west side of Kościelna Street in the post-industrial area. Fears are expressed about the loss of the original character of the district, its historical heritage and architectural style, the alienation of the new thousands of residents and their lack of identification with the local community. Jachowska [7] from Adam Mickiewicz University in Poznań is the most outspoken of these fears. There is hope the prestigious street will avoid degentrification [73].

The social organisation Jeżyce Estate Council has launched an initiative to develop a small square at the beginning of Kościelna Street (at the junction with Dąbrowskiego Street), combining architectural, urban planning and sculptural perspectives. A competition was launched for sculptors and architects working at the University of Arts in Poznań. A dominant design was created, inviting people to enter this historic street. Implementation is imminent.

7. Discussion and Conclusions

In its three centuries of existence, Kościelna Street has been subject to the influences of all the basic pillars (aspects) of gentrification. Despite numerous disturbances, its historical, cultural and architectural identities have not been lost. Nevertheless, some comments are necessary.

The three separate analyses based on these three pillars (economic, social and symbolic) are combined to produce overall results, recognising that some parts of the gentrification process affect others, directly or indirectly.

There is no uniform matrix for gentrification, a flow chart for the process. There are different forms and different rates of progression. Often the nature and course of the gentrification process in African or Asian countries is different from that in Europe. This process depends on many economic actors/companies, the creativity of the city authorities, the needs of revitalisation and the activity of developers. There are always two common elements: financial issues and social groups.

Economists point out that a similar effect that classical gentrification brings is given by financialisation—a process in which financial markets have a greater influence on economic policy [74,75,76]. Considerations mention the financialisation of housing. The results are as follows: housing is treated as a commodity and not as a social benefit. With housing, a quarter of a district becomes a convertible currency. The financialisation of housing is highlighted in the works [77,78,79], while the challenge to the architectural profession in the 21st century proclaimed, among others, by the RIBA in the report ‘Horizons 2034’ is uplifting [80]. The challenge concerns how to position oneself in the face of financialisation. Thus, it is about empowering architects and creating a more equitable and beautiful built environment. The approach in the works mentioned [74,76,80] is connected with the classical concept of gentrification given by Glass in 1964 [10]. It started with the increase in land and building prices, which caused the process of social/population exchange in the central districts of the city.

Gentrification usually proceeds in the spirit of neoliberalism (market fundamentalism) This was also the case with the gentrification of Kościelna Street (one wave after the Jeżyce district was incorporated into Poznań in 1900, the second after the change in the political system in 1990). It is evident from the facts stated above that since 2013, neoliberalism has begun to evolve towards ordoliberalism: freedom yes, but within a framework of order (issues of socio-economic order take precedence) [81,82,83,84]. This is thanks to the growing sensitivity of local community, the activity of the local government (e.g., Initiative:Open) and even the students of Poznań universities.

It is not the architects themselves who have created the gentrification of Kościelna Street. The same is true of a number of other cases known in the literature [85,86,87,88]. It is the resultant effect of many actors, events, economic and sometimes political conditions. The actors in the gentrification process are of varying degrees of dependence on each other, of varying degrees of decision-making and of varying degrees of influence on the gentrification process. The history of creeping gentrification is all the more indicative of the absolute overlap between the gentrification process and architecture. This qualifies for separate studies—see: Schumacher [89] and Buchanan’s reply [90] on autopoiesis in architecture. But, a review of the problems, aspects and effects of gentrification itself reveals another important question. Namely, the activities of the above-mentioned actors, including architectural and urban design, should be guided by a kind of work ethos. Unfortunately, matters of ethics and ethos tend to be overlooked in the literature on gentrification (not just the predatory kind). Would that be tacit acquiescence to simply operating in one form of ‘political capitalism’?

Yes, in the market for the revitalisation of streets and neighbourhoods, it is also possible to see particular cases of action in the light of neoliberalism, action without ethos. Two pathological phenomena, among others, are ‘lurking’ in the revitalisation, which is supposed to ennoble the housing substance and society: buy-outs for rent (especially short-term [91]) and house flipping, i.e., buying flats with the aim of reselling them quickly at a profit. The latter involves exploiting information asymmetries in the level of market knowledge between buyer and seller [92].

A major problem is the lack of adequate research methods for gentrification, taking into account its multidisciplinary character. Science has not yet developed methods at the intersection of historical identity, architecture, social and financial domains. Only sub-tasks (from a single pillar) are solved, which are anyway dependent on the nature of the data and the means of obtaining them. Examples of partial solutions are presented in Section 2 and Section 4.1, e.g., [22,34]. Section 4.2 mentions more than a dozen approaches identifying the attractiveness of a street. Only an example with the Net Promoter Score (NPS) is presented more extensively, which highlights the significant role of the so-called pioneers in shaping opinion. It is not a scientific method, but it is helpful in marketing activities, in shaping attitudes towards a product or institution. In this case, this is the first attempt to apply NPS to the evaluation of design solutions in architecture. From the brief review of the mentioned approaches pointed out in Section 4.2, it is clear that high hopes should be placed on the method of analysing syntactic space. It can already be seen that the Space Syntax methodology is useful at every stage of planning. With its help, it is possible to describe and explain spatial relationships as well as to predict the consequences of design decisions. Interesting examples of the use of Space Syntax in design activities are presented in the works [46,93,94,95]. In general, there is an urgent need to develop research methods in the area of gentrification phenomena, and this will not happen soon.

It is easy to see that the above considerations ignore environmental considerations—one of the fundamental pillars of sustainable development. Gentrified areas face environmental challenges. This usually leads to potential habitat degradation, even rapid urbanisation with the characteristics of classic gentrification. Fragmentation, degradation, habitat loss and pollution continue to increase. There is hope in green models of gentrification: green spaces created and maintained by local communities define green urbanism. Herruzo-Domínguez et al. [21], Ramneantu and Marat-Mendes [96], Uribe-Toril et al. [97] among others raise the alarm about it. The relationship between green spaces and socio-economic problems is outlined by Dash and Chakraborty [98]. A review of the literature on green gentrification is presented by Gou et al. [99]. Attention was already drawn to this problem during the 2012 Venice Biennale (Angotti [100]). After all, the detail related to water retention had a significant impact on the withdrawal of the student designs. The issue of gentrification cannot be pigeonholed into just three pillars.

The example of Poznań’s districts and other cities (not only in Poland) proves that revitalisation policies lead to gentrification [2,3,14]. The point is what course it takes and what character it has. If in most cases gentrification begins with revitalisation, in Kościelna, it began with hunger and economic collapse. From that moment on, the creeping gentrification of the small village of Jeżyce began, which in time turned into the attractive Kościelna Street.

The historical data presented above show constant social and political changes since the 18th century, while the oval layout of the street remained the same. The introduction of peasants from Bamberg is crucial in this case. There is a theoretical dispute as to whether this immigrant population was local or so-called pioneers. In classic gentrification, we distinguish at least three groups of participants in the process: the native or indigenous population (this is the initial social stratum), the pioneers (mainly students and bohemians) and the gentrifiers proper (wealthy and well-educated people). And yet, the Bambers settled on empty, uncultivated fields. The process of assimilation is also interesting. Architecture evolves from homestead to frontage. The process of assimilation has clear periodic accelerations and decelerations (wars, politics, economic crises, Prussian decrees and communist resentment towards the descendants of the settlers). Today, the settlers around Poznań, almost wiped from memory in the second half of the 20th century, take pride in the Society of Poznań Bambers (since 1996) and the Museum (since 2003). In 2009, the Society of Poznań Bambers was awarded the European Citizen’s Prize by the European Parliament for its work on European integration and understanding between peoples. In festive processions, descendants of the settlers participate in characteristic folk costumes.

The architecture itself creates added value, which is greatly enhanced by the actions and involvement of, e.g., students, Poznań universities, the goodwill of local councillors and pro-social initiatives. It is mainly the inertia of citizens that overshadows the essence of sustainable development and sets the tone for gentrification in the original (negative) sense. It is therefore useful to understand the processes involved, to support them skilfully and to engage in the public sphere.

Studying the development of Kościelna Street, as well as the entire Jeżyce district, one can see how important the social and symbolic aspects of gentrification are: it is not only the design solution but also the people, the residents, who complete the value of the street. Understanding and looking critically at gentrification are indicators of a society’s maturity.