The Patronization of Pluvial Flood Risk and Adaptation Among Tenant-Owned Housing Associations in Sweden

Abstract

Pluvial floods are increasingly affecting urban areas worldwide. Despite growing media attention and clear owner responsibility for reducing climate-related risk for buildings in Swedish national adaptation policy, adaptation action remains slow. Understanding how different property owner categories view and act on flood risks is key for developing better incentive structures and support for accelerating adaptation action. While tenant-owned housing is a common form of housing tenure in Sweden, studies are lacking. This study enhances understanding of pluvial flood risk and adaptation views and actions by tenant-owned housing associations in two Swedish cities. It is based on assessments of 69 apartment buildings within eleven tenant-owned associations and semi-structured interviews with their eleven chairpersons. The study indicates that tenant-owned associations grossly underestimate their flood risks and responsibilities for climate adaptation, even though many buildings studied are at significant risk, and most associations have been impacted by floods, some severely and recurrently. The patronization of flood risk and responsibility for adaptation is attributed to several factors: underestimating risks and consequences, devaluing the benefit of one’s own adaptation actions, lacking knowledge about climate adaptation measures for buildings, and (overly) generous insurance terms. The findings confirm low adaptation action among housing associations, even those with recurring floods, which is concerning given the strong reliance on property-owner adaptation in national adaptation policy.

1. Introduction

With climate change, heavy precipitation is intensifying, increasing flood risks in built environments [1]. In many parts of the world, floods caused by heavy precipitation, here referred to as pluvial floods, have become more common and drastic, illustrated not least by the extensive damage and deaths caused by extreme rainfall in European cities in 2024. Such trends towards more powerful and devastating heavy rains are also found in Sweden [2,3], shown to cause significant damage to buildings and their residents [4,5]. This is demonstrated by the €160 million of insured damage costs as well as the impact on people and socially important operations in the Gävle pluvial flood in 2021 [6,7]. Consequently, adapting the built environment, including buildings and properties, to pluvial flood risks is becoming increasingly crucial.

Similar to other European countries [8], the main responsibility for climate adaptation of buildings and properties in Sweden lies with the property owner [9], making them key actors in the implementation of flood risk mitigation actions. However, despite this designated responsibility, studies indicate that few property owners have implemented climate adaptation measures [10,11,12,13]. Though this topic has generated increased academic attention, there are still gaps in understanding why relatively few climate adaptation measures have been implemented by property owners and how further action can be spurred [10,14,15,16,17]. The few existing studies on how Swedish property owners view and manage pluvial flood risk have mostly examined homeowners [10,13,18,19], and to a lesser extent property and construction companies [11,20]. Tenant-owned housing is a common form of housing tenure in Sweden, but studies of how this property owner views and responds to pluvial flood risk are lacking. Thus, how this property owner category views and acts on flood risks is still unclear, but it is important to study to build knowledge for developing more effective policies and incentive structures for climate adaptation of the built environment.

Related studies on flood risks and adaptation among homeowners generally conclude that homeowners are unfamiliar with evaluating pluvial flood risk, view it as rare and unfamiliar, and even in high-risk areas, tend to underestimate risk and rarely recognize it as something to consider [14,15,16,17]. A described reason for this underestimation is that it can be difficult to understand which factors generate flood risks in buildings, acting as a barrier to implementation [13]. While studies have identified various characteristics that contribute to the pluvial risk of a building, they have not found any statistically significant correlations [21], indicating high diversity in building stocks. However, several neighborhood and building characteristics have been demonstrated to contribute to a building’s pluvial flood risk. Neighborhood characteristics include location in an anticipated floodplain or low-lying area [22], the capacity of the stormwater system/type of sewerage system [5,19], the share of impervious area, and topography [23]. In terms of vulnerability characteristics, studies have found that buildings with basements are flooded more frequently than others [22,24,25,26]. Additionally, vulnerability characteristics include the activities and people residing in the buildings [27] and the location of vital technical equipment [11]. Thus, though the combinations of characteristics that generate risk tend to be location-specific, it may still seem surprising that property owners usually do not connect obvious characteristics such as location in a low point to pluvial flood risk, but this seems to be the case with both private house owners [10,13,18,19] and property companies [6,7,11].

Studies have also analyzed the relationship between property owners’ flood experience and willingness to adapt their property, generally finding that such experience does increase willingness [15]. However, it is also clear that flood experience does not necessarily result in adaptation, as shown in both international [15,16] and Swedish studies [10,13]. Studies of pluvial risk conclude that perceptions of one’s capability to adapt to the risk influence perceptions of pluvial flood risk and adaptation behavior to a higher degree than perceptions of floods as a hazard [15,27]. This is often referred to as coping appraisal, which includes views on the effectiveness of available adaptation actions, one’s ability to implement these actions, and their economic and emotional costs. Studies of Swedish homeowners’ decision to adapt indicate that perceptions of adaptation actions are indeed important, highlighting the need for knowledge about how to adapt [10,13]. For instance, Grahn and Jaldell [10] found that homeowners who had adapted their property viewed themselves as knowledgeable about reducing flood risk. However, very few homeowners considered themselves knowledgeable about flood risks, and a majority stated that they were not sufficiently informed to evaluate whether the property-level flood risk reduction actions surveyed would reduce their flood risk, resulting in a low level of adaptation [10].

Hudson et al. [28] reviewed insurance schemes in European countries and found that existing schemes predominantly focus on recovery after weather events rather than proactively reducing climate risks and enhancing property owners’ adaptive capacity. Studies have shown that it is challenging to find insurance schemes that successfully promote risk reduction [28,29]. These studies argue that such insurance schemes alone are insufficient, highlighting the need for research into the broader enabling environments and partnership arrangements required to promote proactive climate risk reduction [28,30]. Hudson et al. [31] characterized the Swedish insurance scheme for extreme weather as a semi-voluntary private market, where multiple extreme weather events are combined in a single policy, and the purchase of extreme weather event insurance is connected to a more commonly required product [28]. This implies that the home insurance of most Swedish homeowners covers floods, but the extent and type of damages covered vary, causing concern among Swedish homeowners who have experienced pluvial flooding [13].

A tenant-owned housing association—the property owner category addressed in this study—is a form of housing tenure where tenants co-own apartment buildings or small houses, regulated in Sweden by the Tenant-ownership Act [32]. By buying an apartment or semi-detached house, tenants get the right to reside in one of the apartments/houses and become members of the association [32]. Tenants are responsible for maintaining the interior of their apartments/houses, while the association is responsible for the property including common areas, water and electricity piping, roofs, facades, garages, and yards. Members pay a monthly fee to cover the operation and maintenance of the property. Tenant-owned housing associations are an increasingly common form of housing tenure in Sweden. In 2021, 42% of all apartments in apartment buildings in Sweden were in tenant-owned housing associations, a share that has increased over the last few decades [33]. Apart from making up a significant share of urban buildings in Sweden, tenant-owned housing associations are an interesting form of housing tenure to study because their tenants are laypeople, such as homeowners, but their buildings are similar to those owned by residential property companies. The board of the association is led by one of the tenants acting as chair, coordinating and interacting both with the property manager and the other tenants. This puts the chairperson in an important strategic position, mandated to lead the maintenance of the property in a changing climate. Researching the views and actions of such key actors in climate adaptation has been identified as pertinent in the climate adaptation literature, particularly regarding the role of private actors [20,34].

This study aims to enhance the understanding of pluvial flood risk in buildings and how flood risks and adaptation are viewed and acted upon within tenant-owned housing associations. The study is based on assessments of 69 apartment buildings within eleven tenant-owned associations and semi-structured interviews with the eleven chairpersons of these associations in two Swedish cities. The study is guided by three research questions:

• RQ1: To what extent and how are the assessed tenant-owned apartment buildings exposed and vulnerable to pluvial floods, and how are pluvial floods experienced and flood risks perceived by the interviewed chairpersons?
• RQ2: How have the analyzed tenant-owned apartment buildings been impacted by pluvial floods, and what are the reasons why these buildings have been flooded?
• RQ3: What actions did the associations take during and after a pluvial flood, and how are climate adaptation actions perceived by the interviewed chairpersons?

This article is structured as follows: Section 2 contains the materials and methods used. Section 3 presents the results divided into five sections, covering all three RQs. Section 4 discusses the results, and Section 5 concludes.

2. Materials and Methods

This study employed a desk study to assess pluvial flood risk of 69 apartment buildings within eleven tenant-owned associations and eleven semi-structured interviews with the chairperson of the respective association to analyze how flood risks are viewed and acted upon by the associations through the eyes of its chairperson. The study understands risk as the potential for adverse consequences caused by climate-related events, recognizing the dynamic interaction between hazards, exposure, and vulnerability [1,35]. The IPCC defines hazard as the potential occurrence of a physical event that may cause loss to property and infrastructure [36]. In this study, we researched how the housing associations’ chairpersons perceived the potential occurrence of pluvial flood events (Section 3.1). In terms of exposure, studies of pluvial flood risks commonly suggest that exposure is influenced by the location of the building, local topography, and the portion of impervious surfaces. In this study, we report data on the pluvial flood exposure of the housing associations according to flood risk maps (Section 3.1), the chairpersons’ views on what determines whether their property is considered at risk, and reasons why the buildings were flooded (Section 3.2) and mechanisms through which the buildings were flooded. Vulnerability encompasses both the sensitivity of the buildings, namely, to what extent the property owner views that the building will be impacted by a pluvial flood, and their adaptive capacity, namely, their ability to overcome the consequences [35]. The level of sensitivity of the buildings depends on the capacity of the sewage/drainage system, whether the building has a basement, the existence of openings, and the placement of indoor vital equipment [11]. In this study, a table contains occurrence and frequency of sensitivity characteristics such as ground floor apartments, basement stairs, and garages. Moreover, physical and financial consequences of the pluvial flood in focus are reported in Section 3.3. Section 3.4 and Section 3.5 present actions performed during and after the pluvial flood as well as the housing association chairperson’s views on adaptation actions, addressing issues of adaptive capacity.

Building on the author’s ongoing collaboration with the umbrella organization for tenant-owned housing associations in southeastern and central Sweden, Riksbyggen, the study zoomed in on associations in the two mid-sized cities Linköping and Gävle. The cities have been affected by pluvial flooding to varying degrees, which were seen as an opportunity to capture a wide range of experiences and perspectives. In 2021, Gävle experienced national record-breaking precipitation [37] with return periods of about 3900 years, resulting in 6830 insurance claims exceeding €160 million in insured damage costs and impacts on welfare buildings [6,7]. Linköping has been affected by minor cloudburst events. In 2018, heavy precipitation flooded basements, a shopping area, and the central railway station.

Also, within the two cities, efforts were made to capture a heterogeneous set of associations. Thus, associations with varying degrees of pluvial flood exposure and sensitivity characteristics were identified through assessments of flood risk mappings of a 100-year rainfall event for Gävle [38] and Linköping [39] and through dialogues with staff from Riksbyggen. The pluvial flood exposure of the housing associations buildings was categorized using these flood risk maps as follows: high exposure >0.3 m water expected at least on one side of the building; medium exposure = 0.2–0.3 m water expected at least on one side of the building; and low <0.2 m water expected at least on one side of the building.

Through the dialogues, the association’s size, building type, and building year were weighed in to ensure a heterogeneous sample. In both cities, Riksbyggen staff acted as door-openers [40], initially contacting the chairpersons to ask if they were willing to participate in the study. Most associations asked agreed to participate. The researcher then contacted the chairpersons to inform them about the study and to schedule and conduct the interview. The size of the sample allows for theme saturation in the interviews, following the recommendation in Wutich et al. [41].

Based on data retrieved from the websites of the eleven housing associations, the study covers 1954 apartments in 69 buildings owned by the eleven tenant-owned housing associations, ranging from 42 to 627 apartments per association, with construction years from 1949 to 2017. The sample also includes a variety of building types, such as high-rise buildings, three-story buildings, and terraced houses, which are common in both tenant-owned housing associations and the current built environment in Swedish urban areas.

In total, eleven interviews were conducted: six in Gävle (G1–6) and five in Linköping (L1–5). All interviewees were chairpersons of the board (

Table 1. Background data and information about the tenant-owned housing associations and the interviews.

Interviewee/Housing Association	Details	Date	Length
Gävle 1 (G1)	47 apartments, 3 buildings, 4 stories, 2016	20220324	61 min
Gävle 2 (G2)	47 apartments, 8 buildings, terrace houses, 2 stories, 1973	20220325	140 min
Gävle 3 (G3)	42 apartments, 1 building, 6 stories, garage, basement, 1983	20220324	58 min
Gävle 4 (G4)	59 apartments, 3 buildings, 3 stories, basement, 1959	20220322	68 min
Gävle 5 (G5)	121 apartments, 3 buildings, 3–7 stories, basement, 1958	20220325	72 min
Gävle 6 (G6)	79 apartments, 3 buildings, high-rise, basement, 1966	20220324	54 min
Linköping 1 (L1)	129 apartments, 4 buildings, 4–6 stories, basement, 1985	20210414	62 min
Linköping 2 (L2)	380 apartments, 7 buildings, 3 stories with basement, 1953	20210416	62 min
Linköping 3 (L3)	627 apartments, 22 buildings, high-rise, garage, basements, 1955	20210423	105 min
Linköping 4 (L4)	284 apartments, 7 buildings, 3–5 stories, garages, 1949	20210424	117 min
Linköping 5 (L5)	139 apartments, 8 buildings, 2 stories, basements, 1963	20210427	46 min

), and, unintentionally, all were older men. The interview guide was based on questions about experiences with floods, their impacts, responses, and views on flood hazards, exposure, vulnerability, and responsibility. All interviewees provided informed consent before the study began, and they were free to withdraw at any time, and confidentiality was strictly maintained throughout the study.

All interviews were audio-recorded and transcribed. The transcripts were analyzed and coded based on the different elements of risk described above. An individual analysis of each transcript was followed by a comparative analysis to identify patterns, similarities, and differences. The main findings for each research question are presented in the results section below. The use of quotes from interviewees substantiates the analytical conclusions, and while striving to capture the main patterns in the material, individual perspectives are also presented to highlight distinctions.

3. Results

The results section presents findings from the desk study and interviews divided into five sections. The first section addresses RQ1, focusing on found pluvial flood risks for the assessed buildings and flood experiences and perceptions about flood risks among the interviewed chairpersons. The second and third sections address RQ2, reporting on reasons why the analyzed tenant-owned apartment buildings have suffered flood damage or not and on consequences of the experienced pluvial floods. Sections four and five address RQ3, presenting the actions taken by the tenant-owned apartment associations to reduce risk and damage during and after a pluvial flood and the chairpersons’ perceptions about reactive and proactive climate adaptation actions.

3.1. Pluvial Flood Risks, Flood Experiences, and Perceptions About Flood Risks

Altogether, weighing both exposure and sensitivity components, the pluvial flood risk was quite high on average in the assessed buildings but differed both between and within the associations.

The exposure, according to flood risk maps, ranged from low in three tenant-owned housing associations, medium in two, and high in six (

Table 2. Tenant-owned housing associations’ pluvial flood risk experience, exposure, sensitivity characteristics, and expectation of pluvial flood in the future based on the desk study and interviews.

Housing Association	Exposure	BAS	BST	GF	Experience	Future Flood Expectation
G1	High			A, G	Single	No, very unlikely
G2	High	A		A, G	Multiple	Yes
G3	High	G			Single	Unlikely
G4	Medium	A, B	X		Single	Yes
G5	Low	B			Single	Yes
G6	Low	C		G	Multiple	Yes
L1	Low	G		A	Single	No, very unlikely
L2	High	G	X	A, P, G	Multiple	Yes
L3	High	B, C		A, G	None	No, very unlikely
L4	Medium	G	X		Single	No, very unlikely
L5	High	X	X	A, G	None	No, very unlikely
Tot		In 42 of 69 buildings	In 12 of 69 buildings	In 36 of 69 buildings

GF = ground floor. GF A = ground floor apartment. GF G = Garage on the ground floor. GF P = Preschool on the ground floor. BAS = Basement. BAS A = Apartment in the basement. BAS B = Business space in the basement. BAS C = Common room in the basement. BAS G = Garage in the basement. BST = External basement stairs. High exposure >0.3 m of water expected at least on one side of the building. Medium exposure = 0.2–0.3 m of water expected at least on one side of the building. Low <0.2 m water expected at least on one side of the building.

). In all associations but two, the exposure of individual buildings varied considerably within the association. In these associations, all buildings were either categorized as high (L3) or low (L1) exposure.

Regarding the sensitivity of the tenant-owned housing associations’ buildings, there were basements in 42 of 69 buildings across ten associations, with five of these basements housing apartments, businesses, or meeting rooms. Technical installations were always located in basements in buildings with basements. In total, there were apartments on the ground floor in 36 of 69 buildings across six associations, and one association also had a preschool on the ground floor. Additionally, 46 of 69 buildings in nine associations had garages, with four of these garages located in basements. Twelve buildings in four associations had external stairs leading to the basements, where only a few centimeters of surface water would be needed to flow down to the basement door, many of which were not waterproof.

In terms of personal experience with pluvial floods, the interviews established that nine of the eleven chairpersons, including all six from Gävle, had personal experience with pluvial flooding of buildings within their association. Three interviewees had multiple experiences, which they came to realize only after the most recent flood event. Interviewees with personal experiences described the pluvial flood event as dramatic and stressed that the event was unexpected.

All three interviewees with multiple pluvial flood experiences expected that their association’s buildings would be at risk for pluvial floods in the future. Surprisingly, their answers still allowed for some uncertainty: ‘Since it [pluvial flooding] occurred again, you really should think: Could it happen again?’ (G2). This suggests that despite recurring pluvial floods, the chairperson still hesitated and said that future floods should not be taken for granted.

The views of future flood occurrence among interviewees with single experience diverged. Some interviewees considered their buildings at risk: ‘So we’re pretty sure that it [pluvial flood] will happen again’ (G4), while others were more hesitant: ‘If we look at the climate, it’s not impossible’ (G3), or believed pluvial floods were unlikely because they understand pluvial floods as very rare events: ‘We have considered if there will be another flooding … but hardly in our lifetime’ (G1). Contrary to what would be expected after experiencing a pluvial flood, these interviewees believed it would not happen again, indicating risk denial.

Interviewees without personal pluvial flood experience did not consider their association’s buildings at risk of future pluvial floods, even if they readily identified external basement stairs as the likely flood mechanism. This appeared to stem from a low perceived flood exposure, as illustrated by the following statement: ‘I can’t see that we currently are [at risk], unless the river Stångån rises ten meters’ (L3). Interviewees without personal pluvial flood experience were informed about the location of the tenant-owned housing association’s buildings on a pluvial flood risk map and the building’s sensitivity characteristics, identified through the desk study, contributing to the pluvial flood risk of their buildings. This information did not influence the interviewees’ view of the pluvial flood risk facing their association’s buildings. Contrary to what the maps and desk study suggested, the interviewees referred to factors such as location in a heightened part of the city or on a slope, or very local topographical and building characteristics that were not accounted for on the map to support the view that their property would not be flooded in the future. Consequently, they did not consider their buildings at risk, regardless of the expected inundation levels represented on the pluvial flood maps.

Moreover, interviewees who connected pluvial flooding to climate change stated that this would make pluvial flood events more frequent in the future. However, since they considered pluvial flood events to be very rare, they struggled to make sense of and expressed doubts about what more frequent rainfall events would entail for something very rare. They reflected on the probability of a similar cloudburst to the one in Gävle in 2021: ‘…some prognosis said that there will be twice as many cloudbursts in the future… The problem with weather, though, is that you’ll never know’ (G2).

3.2. Reasons Why Buildings Have Been Flooded

Altogether, basements were flooded in all nine flood-damaged associations, and ground floors in four of them. While the interviewees could clearly describe which parts of the buildings were inundated, they struggled to ascertain the mechanisms through which the buildings were flooded and the exact locations where the water entered. The reported flood mechanisms spread evenly across surface openings, sewer backups, and other openings (

Table 3. Pluvial flood mechanisms, consequences, and damage cost estimates.

Housing Association	Flood Mechanism	Consequences	Cost *
G1	Surface via entrances, elevator shafts, possibly foundation	Evacuation, ground floor apartments, electricity, storage	Total: €100,000 Own: 12,000
G2	Multiple: Surface via entrances and basement floor drains	Ground floor apartments and basement rooms, electricity, storage	Total: €500,000 Own: 20,000
G3	Multiple: Surface via entrances and garage door and top floor balconies	Ground floor apartments and basement rooms, elevators, storage, garage	Total and own: €20,000
G4	Multiple: Surface via entrances and drains outside basement garage	Basement apartment, business space, common room, garage	Total: €50,000 Own: 40,000
G5	Ground water through foundation	Basement common room incl. kitchen, sinkhole	Own cost: €10,000
G6	Multiple: Ground water through foundation and stormwater pipe burst	Basement common room incl. kitchen, storage, pipes	Do not know
L1	Multiple: roof windows and stormwater pipe burst/leakage	Ground floor apartments, garage, storage	-
L2	Multiple: Surface via entrances, windows, basement floor drains, and basement stair drains	Ground floor apartments (minor) and basement common room, garage, storage	-
L3	External basement stair drains	Do not think anything would be damaged	N/A
L4	Multiple: basement stair drains, garage door, foundation, and chimney	Garage, storage, possibly new basement apartment	-
L5	Some external basement stair drains	Do not think anything would be damaged	N/A

* The damage cost estimates reported here are either based on the costs that had occurred at the time of this study or the interviewee’s best estimate.

). Six of the nine interviewees with personal pluvial flood experience contended that water entered the building through multiple mechanisms. Six interviewees reported surface openings, mainly entrance doors, whereas five identified that the flood occurred through backflow from sewage or stormwater pipes, mainly from drainage wells. Six interviewees noted other mechanisms, including from the building’s foundation due to high groundwater or latent openings in roofs, on balconies, or windows. Interviews without personal pluvial flood experience identified external basement stairs as the likely flood mechanism in their buildings. Interviewees considered that improved knowledge about flood mechanisms would facilitate identification of actions to reduce the pluvial flood risk of their buildings. However, no interviewee reported any plans to analyze where the water entered their association’s building(s).

Apart from these reasons, the interviewees with flood experience frequently referred to the insufficient capacity of the urban piped sewage or stormwater systems as a reason why their buildings were flooded. For example: ‘Their [the municipality’s] stormwater pipes cannot swallow the large quantity of water that came then [during the pluvial flood event], and we can’t do anything about that. The municipality must deal with that’. (G4). This shows that tenant-owned housing association chairpersons tended to displace responsibilities for both the problem and undertaking adaptation responses to someone else, disavowing their own responsibility and role, as specified in national adaptation policy. It also indicates hopelessness and a sense of limited control over adapting their properties, i.e., they viewed that property-level adaptation would not make any difference to the building’s pluvial flood risk.

3.3. Impacts and Damages of the Pluvial Flood

Contrary to the researchers’ expectations, the interviewees with personal experience of pluvial flooding considered the impacts of the pluvial flood as tolerable, regardless of the magnitude and type of damage they had experienced. Even in the case where tenants had to be evacuated from their home for a long period of time, this was seen as tolerable, although interviewees contended that tenants did not want to evacuate and reported that some families decided to stay in their flooded apartments. Six interviewees reported damaged apartments on the ground floor or basement, viewed as aggravating the severity of the impact but still referred to as tolerable since there were no impacts on human health. No interviewee reported any personal injuries, but one interviewee was worried that tenants would be exposed to electricity in the basement, despite having advised them not to go there. Interestingly, one of the associations had recently constructed a basement apartment and, during the interview, realized that it would probably be damaged during a pluvial flood event. Since the interviewee had previously stated that impacts on people’s homes were important to avoid during a pluvial flood, this caused some concern. This example also illustrates how low pluvial flood risk awareness can lead to higher risk. In six associations, the study found impacts on rented business spaces, referred to as unfortunate but unavoidable, and/or common rooms, referred to as tolerable. If a flooded building had an elevator, the elevator was commonly damaged, but this was referred to as tolerable damage because they were only out of operation for a day or two.

All interviewees with pluvial flood experience reported damage in basements, such as storage areas, garages, bike storage, laundry rooms, and common rooms, which were all referred to as minor damage. The flood mainly caused material damage to floor and wall construction materials, along with furniture and tenants’ possessions in basement storage. Destroyed possessions were referred to as minor damage and were mostly viewed as a question of how to dispose of the rubbish. This is understandable since these damages are covered by the tenants’ home insurance. However, two interviewees reported that damages to possessions had caused more severe impacts on already vulnerable tenants, including a woman in grief who had not cleaned out the properties of the deceased.

The study also found long-term consequences. For example, a hair salon located in a basement was damaged and restored, but the hairdresser noticed a bad smell afterward, triggering a new round of moisture measurement and investigation. The interviewees also noted that tenants were eager to notify them about any bad smells or indications of mold, signaling a worry that the water damage might have long-term consequences. Consequently, the interviewees indicated that moisture measurement became a preemptive strategy for both compliance with insurance company requirements and taking precautions against future water-related damage.

Financially, the study found large differences between estimations of both total damage costs and insurance-covered costs (Table 3). Interviewees’ estimates of total costs ranged from €10,000 to €500,000, and their estimates of costs to be covered by the tenant-owned housing association ranged from €10,000 to €40,000. These cost estimates, however, did not include costs covered by tenants and their home insurance, which are likely to be considerable, particularly in cases where apartments were damaged. All interviewees with personal experience of floods referred to costs as manageable and not causing any financial risk for the association. Interviewees emphasized that, due to a requirement to set aside maintenance funds and a high annual turnover, the financial solvency of their association was high. As one chairperson stated, ‘Even if we suffer a million in damage, it’s not much compared with our annual budget of 8 to 9 million’ (L4). All tenant-owned housing associations housing cooperatives were insured, adding to their economic solvency and significantly reducing the cost covered by the tenant-owned housing associations that were significantly damaged.

The two interviewees without pluvial flood experience did not think anything important would be damaged.

3.4. Actions During and After the Pluvial Flood

Interviewees with flood experience clearly described that the handling of the pluvial flooding was very time-consuming, including initiating and maintaining contact with insurers, construction companies, service providers, and worried tenants. This created a stressful situation for the chairpersons, also seen as a minor issue. The interviewees noted that the fact that most people were working from home due to the COVID-19 pandemic facilitated the handling of the pluvial flood: ‘It was very lucky that most board members were working from home. Corona was here a blessing in disguise’ (G2).

Interviewees with pluvial flood experience all responded by removing the water, dehumidifying, and removing damaged building material, seen as comprehensive, protracted, and time-consuming, albeit uncomplicated (

Table 4. Pluvial flood actions performed by the housing associations during and after the flood event divided into reactive and proactive responses.

Housing Association	Actions During the Flood	Reactive Actions	Proactive Actions
G1	Pumping, dehumidify, remove building material.	Temporary barriers considered but dismissed	Sensitivity-reduction
G2	Pumping, dehumidify, remove building material.	Backflow valves considered but dismissed	Sensitivity-reduction, possibly assessing risks systematically
G3	Dehumidify, remove building material.	Balcony drainage, watertight entrance doors	No, do all we can and is outside our own control
G4	Pumping, dehumidify, remove building material.	-	Sensitivity-reduction, possibly watertight entrance doors
G5	Pumping, dehumidify, remove building material and furniture.	-	No, done all we can, sensitivity-reduction
G6	Pumping, dehumidify, remove building material and furniture.	-	Possibly assessing groundwater flood risk
L1	Dehumidify, remove building material.	Stormwater pipes and drains, entrance roofs, sealed roof windows	Never thought about it and no need
L2	Dehumidify, remove building material.	Improved infiltration, basement stair gutters, waterproof windows, greenery. Considered backflow valves but dismissed. Considered waterproof entrance, basement and garage doors but not allowed.	Discouraged by cultural heritage restrictions and outside one’s own control
L3	-	Restored surface slope.	No need to reduce pluvial flood risk
L4	Dehumidify	Improve drainage; plugged garage drains. Chimneys planned whilst roofs are to be renovated. Considered basement stair roofs but dismissed	No need to reduce pluvial flood risk
L5	-	-	No need to reduce pluvial flood risk

). Due to the many damaged buildings in the Gävle pluvial flood event, the availability of dehumidifiers and pumps was severely restricted, protracting the response time.

Regarding reactive actions to rebuild damaged parts of the buildings, four interviewees stated that they had corrected one or more particular mechanisms observed during the pluvial flood, including sealing windows, waterproofing doors and windows, and plugging basement drains.

The study also found that four associations had considered but dismissed actions frequently promoted as viable by insurance companies, such as backflow valves, temporary flood barriers, and entrance door roofs. Disregard was motivated by a perceived low effectiveness or being unaesthetic. One association had considered a range of reactive actions but was unable to implement them due to cultural heritage rules.

The study found that four associations had taken action to reduce the building’s sensitivity, i.e., decrease damage in case of a future flood event. The sensitivity-decreasing actions, such as using inorganic materials and paints, did not happen automatically and were only implemented because they were suggested by an employee of the cooperative’s property manager, which most tenant-owned housing associations have contracted and regarded as a trusted source of knowledge.

Further, no interviewee reported that they had performed any actions to systematically assess and proactively reduce the pluvial flood risk of their buildings. In terms of planned adaptation actions, at the time of the study, i.e., at least ten months after the pluvial flood, only three interviewees, two of whom had multiple experiences, stated that they were considering assessing the pluvial flood risk of their buildings in the future. For one of them, the assessment would only consider a specific type of flood risk. Two interviewees who were expecting future flooding of their property stated that they believe they have done all property-level adaptation action they could do, referring to further adaptation action being constrained by other actors, mainly the municipality. Three interviewees with flood experience reported no plans, stating that they had never given pluvial flood risk reduction a thought because they did not expect any future flooding of their property. Evidently, the two interviewees without pluvial flood experience, despite high pluvial flood exposure according to flood risk maps, saw no need for actions to reduce pluvial flood risk.

3.5. Views of Reactive and Proactive Adaptation Actions

The actions implemented by the tenant-owned housing associations are predominantly reactive. According to the interviews, this reactive approach aligns with how their association responds to other building and technical equipment failures. However, such a reactive approach, without a learning ambition, clearly has its limitations. It neither facilitates correcting other similar failures nor understanding their root causes. The interviewees referred to reactive actions as uncomplicated compared to preventive actions and generally expressed a strong sense of control over reactive actions, believing them to be sufficient to protect their buildings from pluvial flood damage in the future.

In contrast to the interviewees’ favorable view of reactive actions, their statements clearly indicate that preventive actions in general, and actions to reduce pluvial flood risk in particular, were highly unlikely to occur. Interviewees agreed that preventive actions lacked a clear purpose or benefit, illustrated by the following statement: ‘It’s not like we’ll dig up some pipes in preventive purpose to prepare for the future. We’ve never done that and have no plans to do that either’ (L4). The way the interviewees discussed preventive actions indicates both a lack of awareness of how pluvial flood risks could be reduced and a fear that the effectiveness of such actions would be severely constrained, as they depend on complementary actions outside the property boundary being implemented by other actors, mainly municipal departments. As one chairperson stated, ‘But I also think that we have an external influence, where we can’t affect. Ultimately it [the responsibility] must be placed on the municipality, in my view... we can’t change that. We depend on the municipality’ (L2). The above is particularly important in view of the expectations in the Swedish national climate adaptation policy, which clearly assigns the responsibility for climate adaptation in the urban built environment to property owners [7,12].

Another possible explanation of the interviewees’ unfavorable view of proactive actions could be that they tended to view preventive actions very narrowly, predominantly involving the enlarged capacity of sewage and stormwater pipes. This points to limited knowledge about what adaptation to pluvial flood risk could entail and, consequently, what actions were being considered. This is very different from the preventive, often nature-based, adaptation actions discussed in urban adaptation literature. The interviewees viewed pipe-related actions as invisible for the tenants, very costly, and substantially more expensive compared to their perceived minuscule benefits. As one chairperson stated, ‘Underground actions will not be seen. Five years from now everybody will have forgotten about them. Investing many millions that nobody saw, the fee was increased, but nobody felt that they benefited’ (L4). The visibility of actions was clearly seen as important for the interviewees, exemplified with: ‘If you mount photovoltaic panels, they are visible externally, everybody sees them… it feels quite good in everybody’s guts when you look at them’ (L4).

The Interviewees also described a lower degree of control over preventive actions as they fall on the edge of, or outside, the tenant-owned housing association board’s mandate compared with reactive actions. These would need to be decided at the tenant-owned housing associations’ annual meeting, involving all tenants. The chairpersons emphasized that convincing tenants is very difficult.

4. Discussion

Based on assessments of pluvial risk characteristics in 69 buildings and interviews with chairpersons in eleven housing associations in two Swedish cities, the study provides five insights into how this previously understudied category of property owner views and acts upon flood risks and adaptation of buildings.

Firstly, the study showed that none of the eleven tenant-owned housing associations had adapted their buildings to pluvial floods, regardless of the buildings’ level of pluvial flood exposure, sensitivity characteristics, and experienced impacts. This finding aligns with the low uptake of property-level adaptation actions found among homeowners [10,13] and property companies [7,11] in Sweden [12] and abroad [15,16,24]. Many of the tenant-owned apartment buildings examined were at risk for pluvial floods and, consequently, in need of adaptation. This is supported by experiences of flooded buildings in nine of the eleven associations studied, three of them several times, as well as high exposure indicated by expected surface water depth during a hundred-year event exceeding 0.30 m at least in parts of the buildings in six of them. Moreover, the study also found building characteristics associated with pluvial flood risk in all tenant-owned housing associations, such as apartments or businesses in basements in five of the eleven associations. Further, buildings in six associations were flooded through multiple flood mechanisms, indicating a need for property-level adaptation actions. Comparing pluvial flood exposure from the desk study with tenant-owned housing association chairpersons’ views on future flood expectation indicates that they heavily underestimate pluvial flood occurrence, particularly among those with single or no personal flood experience. This underestimation has also been found in studies of other property owner categories in Sweden and abroad [10,15,16]. The study also suggests that merely making flood risk maps available is unlikely to influence the housing association chairpersons’ pluvial flood risk perception and that vigorous action is needed to get this type of property owner to implement climate adaptation measures on/in their buildings and yards.

Secondly, contrary to the researchers’ expectations, the study established that regardless of the type and magnitude of experienced damage during pluvial flood events, chairpersons viewed the damage as tolerable. This view appears to serve as a further reason why the tenant-owned housing association should not engage more with adaptation, similar to a rebound effect [16,17]. This reaffirms the importance of the experienced severity of impacts, rather than experience itself, as an influential factor for shaping individuals’ views of pluvial flood risk [16]. The study suggests that impacts on tenants’ health would likely trigger more engagement with climate adaptation of their buildings. Although evacuation of tenants and flooded business spaces were viewed by the chairpersons as impacts to be avoided, experiences of these damages did not trigger any engagement with proactive climate adaptation in the three associations experiencing these impacts. The underestimation of pluvial flood risk, combined with viewing pluvial flood damage as tolerable, indicates a very low perception of pluvial flood threat.

Thirdly, the financial impact of the pluvial flood was also seen as tolerable, which appears due to the fact that all tenant-owned housing associations were insured, demonstrating a high penetration of flood insurance, similar to other property owner categories in Sweden, but unlike in some other countries [16,24]. The study also found that insurance covered a large part of the damage costs, and the tenants’ home insurance covered most of the cost of damaged possessions, even if the insurer’s final decision was not made in some cases at the time of the study, ten months after the pluvial flood event. Additionally, no interviewee mentioned that their associations’ insurance company had raised concerns about or demanded proactive adaptation during restoration, thus focusing solely on restoring rather than reducing pluvial flood exposure and sensitivity after the flood event, which is in line with experiences of insurance company activity in studies of other types of property owners in Sweden [7,11]. This indicates that insurance conditions and insurance company actions had no or very limited governing effect on this property owner’s attitudes or actions regarding flood risks (cf [28,29]). This is noteworthy considering that insurance companies in many other countries have significantly increased their requirements on insurance takers, increased premiums, and/or separated flood risk insurance [42], even if the general conclusion is that insurance schemes alone are insufficient [28,31].

Fourthly, the study found that tenant-owned housing association chairpersons with personal experience of floods viewed pluvial flood impacts as financially and emotionally less significant than homeowners have done [13,18]. Even though the study found substantial damage costs, the chairpersons deemed these as minor due to their association’s high economic solvency, high share of damage costs covered by insurance, and relatively low costs per tenant. This contrasts with the more substantial economic damage [10,13] and worry about the financial consequences [13] reported by homeowners. Moreover, the chairpersons in this study referred to themselves and their tenants as having high economic solvency, similar to what Jarnkvist [18] found among wealthy white male homeowners positioning themselves as standing above climate risks, or what O’Brien et al. [43] referred to as complacency to climate risk. This could be one more reason for the housing associations’ low engagement with climate adaptation of their buildings.

Fifthly, the study found support for both a low sense of control of adaptation actions and a low perceived need for climate adaptation. Consequently, very few associations had adapted their buildings, and interviewees provided many arguments for why adaptation is unnecessary or ineffective for them. This suggests a weak sense of mandate and perceived capacity to control or make a difference in urban adaptation. This appears underpinned not only by a lack of knowledge of adaptation actions, as also found in studies of Swedish homeowners [10], but also by the chairpersons’ views that many property-level flood reduction actions would be unsuitable for their association due to poor aesthetics and low efficiency. Here, the study found a very restrictive understanding of proactive adaptation actions, primarily seen to involve expensive investments in the pipe-bound sewage or stormwater system. This must be viewed in light of the wider palette of proactive adaptation actions available, often involving nature-based solutions or sustainable stormwater measures, including green roofs, rainbeds and rain gardens, open streams, permeable pavements, and vegetated swales [44,45], which no interviewee referred to. Such measures can reduce pluvial flood impacts and associated economic losses [45] and are also likely to be attractive to tenant-owned housing associations due to their visibility and aesthetics, pointing to a knowledge gap similar to what Grahn and Jaldell [11] found among Swedish homeowners. Moreover, regarding available adaptation actions, the study found that chairpersons’ understanding of adaptation actions was shaped by their favored reactive approach to fixing problems after they had occurred. This approach, when practiced without reflection, fails to result in learning and remedies the symptoms rather than the causes of the pluvial flood risk. The interviewed housing association chairpersons also believed that the cost of adaptation would overwhelmingly exceed its benefits and that the risk to their buildings is foremost influenced by factors outside their own control, similar to findings in studies of homeowners [10,13,18]. This highlights the need to make information about proactive adaptation actions and the role of property owners in urban climate adaptation more widespread.

5. Conclusions

Pluvial floods are increasingly affecting urban areas worldwide. Despite this, available evidence suggests that adaptation actions among property owners remain slow, in spite of clear principles of owner responsibility for reducing climate-related risks for buildings and central roles attributed to property owners in national and local adaptation strategies. A greater understanding of how property owners view and act on flood risks has thereby been requested. In Sweden and many other countries, though, there are yet few studies focusing on how other property owner categories than homeowners views and act on flood risks and adaptation.

This study hones in on tenant-owned housing, which is an increasingly common form of housing tenure in Sweden, making up 42% of all apartments in apartment buildings in Sweden in 2021. The study set out to examine to what extent and how the assessed tenant-owned apartment buildings were exposed and vulnerable to pluvial floods, as well as how the interviewed chairpersons have experienced and viewed pluvial flood risks and adaptation. The study found that a high share of the tenant-owned housing association buildings studied were exposed to pluvial floods, supported both by desk study data indicating exposure and sensitivity characteristics and that nine of the eleven associations had been flooded at least once. Despite this, few housing associations stated a need for proactively adapting their buildings, indicating that they heavily underestimate pluvial flood risks, particularly those with single or no personal flood experience.

The study also found that the tenant-owned apartment buildings were impacted by pluvial floods not only through considerable and prolonged actions to dehumidify and rebuild the damaged parts of the buildings but also through flooded apartments, business spaces, garages, and common rooms, as well as the evacuation of tenants and damage costs of up to €500,000. Regardless of the damage type and magnitude, the chairpersons viewed the damage as tolerable, serving as a reason why they do not have to engage more with adaptation. The underestimation of pluvial flood risk, combined with viewing pluvial flood damage as tolerable, demonstrates a very low perception of pluvial flood threat and, consequently, a lack of reason to engage with climate adaptation.

Moreover, the study found support for both a low sense of control of adaptation actions and a low perceived need for climate adaptation, suggesting a very low perception of coping appraisal manifested as a weak sense of mandate and capacity to control or make a difference in urban adaptation. This, too, provides another reason for their low engagement with climate adaptation.

The study suggests that adaptation of tenant-owned apartment buildings is a complex task for laypeople such as the chairpersons in this study. It was found that sensitivity-reducing property-level actions were only implemented when suggested by a trusted source of expertise, which, in this study, turned out to be a professional property manager. Two further actors were found to have the potential to influence housing associations’ adaptation engagement: municipalities and the insurance industry. Municipalities are recognized as key actors since sewerage departments have a mandate to manage urban stormwater and are attributed responsibility for deficient capacity, aggravating the flood risk of buildings in certain locations. To spur property-owner adaptation, it is found vital that municipalities inform about their adaptation actions, since property owners otherwise remain unaware. The insurance industry had, in this study, no or very limited governing effect on this property owner’s attitudes or actions regarding flood risks since their actions predominantly targeted recovery rather than proactive reduction of pluvial flood risk. This is noteworthy considering that insurance companies in many other countries have significantly increased their requirements on insurance takers, increased premiums, and/or separated flood risk insurance [38]. This points to a potential for insurers to increase the incentives for property owner adaptation.

To sum up, the property owner category in focus for this study—tenant-owned housing associations—largely seems to underestimate pluvial flood risks for their property, even the ones impacted repeatedly. As a rule, they do not implement any proactive adaptation measures. This is alarming given that tenant-owned housing is a common form of housing in Sweden and that property owners have the main responsibility for adapting buildings in a changing climate. Powerful actions from the state, municipalities, insurance companies, and umbrella organizations appear needed both to steer towards a different course of action and to educate the actors about factors contributing to pluvial flood risk, common types of damages, the significant actions needed to restore damage, effective climate adaptation measures, and co-benefits of adaptation. Even though the study concerns tenant-owned housing associations in Sweden, the findings would also be relevant for other property owner categories, especially homeowners who also are laypeople such as the housing association chairpersons studied here. Moreover, since the apartment buildings studied do not differ significantly from such buildings in other cities, especially in northern Europe and North America, the findings related to flood mechanisms, types of damage occurred, actions during the pluvial flood, and reactive actions are likely to be more widely applicable.

Based on the findings in this study, future research should focus on ways to spur housing associations’ engagement with climate adaptation and evaluate the effectiveness of various property-level adaptation actions. Here, studies of nature-based solutions would seem particularly promising due to their visibility and aesthetics. Moreover, studies examining to what extent adaptation action can be triggered by trusted sources of expertise are also needed.