1. Introduction
The decarbonisation of domestic heating is a key pathway to achieving emission reduction and climate targets. Yet, domestic heating transitions are complex because they require not only the adoption of new technologies (Martiskainen et al. 2021; Sovacool & Martiskainen 2020) but also the phase out of carbon-intensive technologies and activities (Hast et al. 2016). Domestic heating systems are entwined with the broader energy and political system, and creating successful decarbonisation pathways depends on understanding both these high-level factors (Vadén et al. 2019) and the impact of everyday activities on the heating transition (Laakso et al. 2021).
Hybrid heating arrangements have gained attention as part of the domestic heating transition. Hybridity in domestic heating is not a uniform phenomenon, but rather an umbrella term capturing diverse technological configurations alongside a complex mix of motivations and challenges shaping the uptake and use of hybrid heating systems in households. These hybrid or stacked heating systems are not merely combinations of technologies but context-dependent ways of using different domestic heating systems based on individuals’ everyday activities, ultimately also supporting household preparedness and resilience.
In Finland, hybrid heating systems vary in their configurations, combining energy sources such as district heating, solid wood, wood pellets, electric heating and heat pumps (Numminen et al. 2024; Ruokamo 2016; Silvikko de Villafranca et al. 2025). Research indicates a general acceptance of hybrid domestic heating systems among Finnish households. For example, in newly built detached houses, previous research identified how preferences for the composition of the hybrid heating system are shaped by diverse factors including investment and operating costs, comfort of use, and the environmental friendliness of solutions (Ruokamo 2016). Improving energy efficiency in Finnish households has been identified as a key benefit of supplementary heating systems. Consequently, promoting awareness of the benefits of hybrid heating and providing incentives for adoption should be at the centre of designing policy measures in this area (Räihä & Ruokamo 2021). Another challenge in debates about hybrid heating systems is the diversity of system configurations and the difficulty of capturing this diversity in statistics on domestic heating solutions in use. Official statistics face the challenge of reflecting this phenomenon as they rely on capturing a primary heating system, overlooking the diverse solutions implemented in practice (Numminen et al. 2024).
Decisions about domestic heating arrangements are influenced by factors beyond efficiency, costs and savings. In the context of phasing out oil heating in Finnish detached houses, practical knowledge and routines in operating the heating system are key factors in individuals’ decisions to embark on an energy renovation to replace oil heating systems (Kajoskoski 2024). The attachment to a specific fuel source, especially using wood for heating, reflects the deep embeddedness of a dweller’s heating and associated activities in everyday life (Jalas & Rinkinen 2016). Citizens also play a key role in setting up and managing their domestic heating systems. With the specific characteristics of designing heating configurations being driven by dwellers, designing policy measures supporting the targeted uptake of hybrid heating solutions in the home is difficult (Silvikko de Villafranca et al. 2025).
Hybrid heating systems are increasingly common, and previous research has highlighted the benefits associated with them (Numminen et al. 2024; Räihä & Ruokamo 2021; Ruokamo 2016; Silvikko de Villafranca et al. 2025). The present paper contributes to a more comprehensive understanding of hybrid heating in the context of sustainable and just heating transitions by focusing on how individuals reflect on and relate to hybridity in their domestic heating system in Finland. Rather than viewing domestic heating transitions as parallel processes of phasing out fossil-fuel based, carbon-intensive systems and the simultaneous phasing in of renewable, low-carbon systems in homes, the intricate ways in which established and new systems interact in the home are explored. These interactions unfold across infrastructures and ways of using systems, resulting in complex stacked heating systems characterised by combining different technologies driven by different motivations and challenges.
In this context, the role of everyday activities—here broadly understood to capture how heating is embedded in everyday life through routines, habits and actions—in enabling access to thermal comfort and enacting care is of importance. Instead of satisfaction with one’s thermal environment (i.e. neutral, comfortable temperature), thermal delight refers to the pleasure, i.e. the positive experiences, derived from a specific or varied thermal environment. Delight also refers to the diverse sensory experiences, including sounds and visuals, provided by different heating modes and is deeply connected to personal heating preferences and the role played by different sources of heat as opposed to thermal comfort’s more static and neutral understanding (De Dear 2011; Heschong 1979; Parkinson & De Dear 2017). The notion of comfort is expanding and evolving, and deeper engagement with comfort can provide an avenue for better understanding changing energy demands (Ellsworth-Krebs et al. 2021). Moreover, recent research increasingly looks at the concept of care in rethinking the understanding and shaping of energy transitions. This has taken the form of exploring how domestic comfort and energy use are co-produced via relational and embodied care activities that in turn are shaped by social dynamics and the existing material infrastructure (Madsen 2018, 2025). Hence, an ethics of care as an alternative to energy justice is proposed to zoom in on the need for contextual sensitivity in energy transitions (Gram-Hanssen 2024). Also, gendered dimensions of care play a part in energy transitions as domestic labour and emotional investments become reconfigured in transition processes that go hand in hand with newly emerging technologies (Strengers et al. 2022; von Platten et al. 2025). The energy–care nexus has been proposed to better grasp the ways in which care both depends on and shapes energy systems, across cultural and socio-economic contexts (Wågström & Michael 2023). Additionally, adaptive and caring energy practices of low-income households are often overlooked in efficiency-driven policy interventions (Woods et al. 2024), highlighting how care is often invisible in policy frameworks.
This paper explores hybrid heating by drawing on personal narratives that provide insights into how people reflect on and relate to the availability of several heating modes in their homes as the result of multiple and gradual transition processes. Diverse factors and motivations underpinning stacking of heating modes in the home are explored in relation to how motivations for stacking of heating modes extend to everyday activities and care.
‘Stacking’ here refers to a user-driven approach to domestic heating in which individuals actively seek out and assemble multiple, often independent, heating modes—including different technical systems as well as behavioural and localised body-warming activities—that can be combined in context-dependent ways to meet diverse needs. These modes may remain dormant, be used occasionally or serve as contingency options, depending on situational demands and preferences. The inclusion of these features allows for a broader understanding of hybridity in domestic heating. Centring personal narratives builds a more nuanced understanding of heating transitions as a social phenomenon, including the layering of systems and activities in domestic heating.
The paper is structured as follows. Section 2 describes the data and methods used. Section 3 gives the findings, which are discussed in Section 4. Section 5 concludes and draws out key implications for domestic heating transitions.
2. Data and methods
A total of 110 oral histories was collected between November 2022 and April 2024 in Finland: the first set was collected in the Joensuu region in eastern Finland in the 2022–23 winter; and the second set was gathered in the Tampere and Lahti regions in southern Finland in the 2023–24 winter. The oral histories are part of the international JUSTHEAT project which uses oral histories and art methods to understand the experiences of heating change across time and place (Ambrose et al. 2023).
Oral histories as a method (Ambrose et al. 2024; Goodchild et al. 2017) allow complex and in-depth personal narratives on a specific topic, in this case domestic heating transitions, to be captured. While the interviewer provides a broad framework, the topics covered in the oral history are decided upon by the participants themselves in line with where they focus their personal narrative. The oral histories capture personal heating stories from early childhood to the present, focusing on key elements and experiences in the participants’ life. Thus, the oral histories reflect a variety of housing and heating arrangements. Oral histories are open-ended, participant-led conversations that aim to capture a holistic understanding by giving participants the space in which to narrate their own experiences, memories and perspectives (Leavy 2011). As such, they provide room to focus on the everyday aspects of transitions (Ambrose et al. 2024; Goodchild et al. 2017), opening up the deep complexity of changing domestic heating arrangements.
Recruitment relied on building networks with local actors who in turn supported the research team in contacting possible participants in each case study location. Additionally, the research team actively reached out to possible participants via diverse channels such as local events and social media channels of local networks. Participation was based on each individual’s interest and willingness to contribute. This self-selection allowed the inclusion of interested and engaged participants, yet it also introduced limits to representativeness as the dataset may not fully capture the diversity of experiences within the broader population. Still, oral histories provide rich narratives that support a deeper understanding of factors shaping domestic heating transitions.
All oral histories followed a similar structure and started by asking participants to share their first memory of keeping warm at home. Following this, participants were encouraged to freely share those memories and reflections that were of importance to them with minimal intervention from the researchers, who mainly used questions to keep the oral history focused on the topic of domestic heating. This open approach afforded participants the possibility to share a broad set of experiences, instead of focusing only on specific technologies or events.
The oral histories varied in length, typically lasting around 45 min. All oral histories were recorded and transcribed, all with the participants’ consent and with ethical approval. The transcripts were thematically coded using Atlas.ti. Thematic coding (Braun & Clarke 2006; Friese 2019; Linneberg & Korsgaard 2019) meant coding first a subset of oral histories to inductively capture key themes shared by participants. Once a first saturation point in capturing new themes, and creating new codes, was reached, the coding system was refined by clustering similar codes into broader themes and developing subthemes to reflect the richness of the experiences shared. Subsequent oral histories were coded using these refined themes. One central theme in the oral histories was hybridity and its influence on domestic heating. All quotations used in this study were translated from Finnish.
Older participants were overrepresented, with the average age being 60 years. Most participants owned their current home. Given the topic of discussion, the reflections shared by participants in the oral histories extended beyond their current living situation to include a diverse set of past living situations. Table 1 summarises the key characteristics of the dataset.
Table 1
Key characteristics of the dataset.
| CASE STUDY LOCATION | PARTICIPANTS | AGE GROUP (YEARS) | AVERAGE AGE (YEARS) | GENDER | CURRENT HOME IS … | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 20–39 | 40–59 | ≥ 60 | N/A | MALE | FEMALE | N/A | OWNED | RENTED | N/A | |||
| Joensuu | 54 | 7 | 23 | 23 | 1 | 55 | 31 | 23 | 48 | 6 | – | |
| Lahti | 30 | 1 | 4 | 25 | – | 72 | 12 | 17 | 1 | 14 | 13 | 2a |
| Tampere | 26 | 6 | 9 | 11 | – | 54 | 11 | 13 | 2 | 22 | 4 | |
| Full sample | 110 | 14 | 36 | 59 | 1 | 60 | 54 | 53 | 3 | 84 | 23 | 2a |
[i] Note: aOne was owned by the spouse.
N/A = not available.
3. Results
The oral histories present deeply personal accounts of heating experiences across time and place. Participants shared diverse experiences related to heating, keeping warm at home and changes taking place in relation to domestic warmth. A recurring theme was the role played by the availability or lack of multiple heating systems. The oral histories offer rich reflections on hybrid heating over time, highlighting its contextual nature and the diverse motivations underpinning it. This enhanced understanding sheds light on how hybrid heating influences the broader direction of the heating transition.
Hybrid heating arrangements are common in the oral histories, as part of either participants’ current heating systems and routines or their past experiences with domestic heating. Participants’ reasons for stacking are grouped into three broad categories based on the qualitative content analysis described above:
preparedness
thermal delight and everyday activities
the environment.
Additionally, participants reflected on the difficulties in accessing and benefitting from stacked systems. Taken together, these categories provide a holistic picture of individual experiences and motivators for stacking heating systems in the home. In the following sections, each category is unfolded in turn.
3.1 Preparedness
Hybrid heating systems are framed as key contributors to increasing preparedness and resilience of domestic heating to external shocks, such as an energy crisis or interrupted supply due to electricity cuts. Increased preparedness is not limited to a more focused understanding of preparedness but also extends to households’ capacity to prepare for shifts impacting their economic situation. Here, wood plays a key role as the backbone of hybrid heating systems offering households not only flexibility to respond to price developments but also to be independent from larger systems in keeping a warm home in case of disruptions. This is also reflected in Finnish policy strategies that stress the role played by local, solid fuels in enhancing societal preparedness (TEM 2019).
One form of preparedness was identified by those participants living in a more rural setting with a clear appreciation for the flexibility of wood in times of disruptions such as electricity cuts. Here, the appreciation for stacked heating arrangements is shaped by the remote location and the need to be able to react to interruptions to large-scale systems. One participant shared:
Well, the idea is that in a sparsely populated area, it’s good to have both options. If there are power outages, you can still heat the place.
(2_1)
Concerns over preparedness and the dependence on larger systems were also connected to the Ukraine War:
Then, what about the war in Ukraine and all that must have had an effect on it, that it came at such a time that people thought that they really didn’t want to be dependent on anything or anyone.
(3_14)
In this context, one participant who previously used wood pellets reflected on how supply chain issues as a consequence of the Ukraine War, meant a return to solid wood heating:
Actually, we only started using it this year. For over 20 years, we’ve mainly had pellet heating, but due to the Ukraine crisis, we couldn’t get pellets at all. So we had to get a backup and bought a wood stove.
(1_7)
The decarbonisation of heating has been supported with subsidies targeted at detached or semi-detached houses to transition to geothermal, air-to-water heat pumps or district heating (ELY Keskus 2025). In the case of a non-hybrid heating system, participants share feelings of insecurity in relation to domestic heating, especially in the case of relying on a larger system as opposed to having more direct impact on one’s heating. One respondent with a geothermal heating system, and no additional sources of heating, described how they feel less secure in their heating:
I’m dependent on electricity that comes from the utility, and a lot of it, if it’s freezing there is not enough warmth. I need a lot of electricity. It was the same with district heating. Fortunately, there is nothing wrong, there hasn’t been yet, but everybody is dependent on warmth coming.
(3_22)
A respondent with access to a hybrid heating system reflected on the ability to influence one’s own heating more directly in the case of using solid wood and how this brought with it an increased sense of security and preparedness:
Maybe it’s also that you can influence it yourself. It’s something you can do yourself, unlike with electricity, where you’re inevitably at the mercy of others when it comes to fixing it.
(1_26)
Preparedness extended beyond heating homes to include the possibility to prepare food, both as a measure to increase preparedness and to keep cherished attachments alive. The versatility of using wood beyond the provision of heating was a clear factor in retaining ovens in homes. Preparedness was not limited to crisis situations but also encompassed the ability to flexibly adjust and react to fluctuating energy prices, especially in households where electricity was used for heating. This was not only an experience connected to present energy prices but also something participants remembered from heating arrangements in their childhood. Participants shared how, in their childhood home, financial reasons meant a stronger reliance on wood as opposed to electricity for heating:
But somehow, in a detached house, so much electricity is used, especially for heating, if you relied solely on it. Even though it was still cheap back then, we still saved it. Wood was cheaper.
(1_26)
But I do believe that behind it is the fact that it’s seen as cheaper than using purely electric heating in winter. So, there was electric heating, but there was also a hot water tank or water-circulated heating, not underfloor heating, but water-circulated heating. But in a way, it’s been seen that it needs to be supported by wood. And I do believe that money has been a pretty big part of the whole picture.
(3_1)
Still, the period after 2020, which was characterised by more volatile and higher electricity prices (Finnish Energy 2024), impacted households and as shared in the oral histories meant a stronger reliance on solid wood, where possible:
Of course, when you think about it, especially with a bigger house and the current electricity prices, if you’re active and willing to chop and gather wood, it does help financially.
(1_37)
One participant shared how they have actively sought to reintroduce wood into their heating system by restoring the possibility to use solid wood, alongside installing an air-source heat pump to increase their flexibility and to enable them to manage different heating systems in a complementary way:
And then last year, we converted the tiled stove, which had electric resistors, to wood-burning. The electricity prices and the type of electricity contract we had, and how the situation changed, led us to want to use the other fireplace as well, and it actually worked out quite well. […] We also installed an air source heat pump just last year. It’s something the previous family, who lived there for 30 years, didn’t have. It was kind of a time of cheap electricity, or they made solutions like heating the water tanks at night and such.
(3_7)
Relying on hybrid heating set-ups for financial reasons is in several cases also tightly connected to forest ownership, either personal or in the family or wider social networks, and the understanding of wood as free:
And I actually calculated that, especially when I got firewood as a gift from my father, it was very cheap to heat additionally with wood. But even with purchased firewood, based on my rough estimates, it was about half the cost or something like that.
(3_6)
This brings with it consideration of the environmental cost of having access to a hybrid heating system, including the use of solid wood and managing its use in a way conscious of the environmental impact, especially regarding air quality (Savolahti et al. 2019). In cases where stacking is possible, solid wood plays a key role in the oral histories, either as the cornerstone of heating that is then supplemented with other forms, such as electricity or a heat pump, or as the additional heating system kept in a building throughout different iterations of other heating systems.
When discussing preparedness and resilience, participants highlight how especially wood heating allows greater control over their heating. This includes ensuring security of supply, the possibility to react flexibly to supply interruptions, caused by either political crises or extreme weather events, and managing rising or volatile energy prices when having the possibility to avoid using electricity for heating.
While wood is often supplementary, there is a reluctance to phase out the possibility to burn solid fuels at home. The oral histories share a deep attachment to wood as a locally available, easily stacked and stored fuel that contributes to preparedness as well (TEM 2019). In addition, wood gives visibility and tangibility to heating from childhood onwards.
3.2 Thermal delight and everyday activities
In addition to thermal comfort, i.e. a person’s experiences in relation to cold or warmth (De Dear 2011; Parkinson & De Dear 2017), the oral histories also show thermal delight (Heschong 1979) as another key motivator for hybrid heating arrangements.
The role of solid wood is central when discussing hybridity and special attention is given to how heating with wood enhances and contributes to thermal delight alongside enhancing preparedness and flexibility in diverse ways as discussed above. Participants also noted the role of heat pumps in providing cooling and thus increasing thermal comfort.
Closely related to thermal delight, everyday activities are crucial in shaping how hybrid heating solutions are used and valued. The stacking of activities alongside heating systems means an at-times seamless shifting between different routines of keeping warm and their integration with other activities.
Care is also associated with the provision of heating (Madsen 2018, 2025; von Platten et al. 2025; Wågström & Michael 2023; Woods et al. 2024). The possibility to show care was also visible in the oral histories, e.g. in the description of making and stacking firewood for family and community:
We also went to make wood for grandma, who was in poor health, so mom went there to make firewood for her.
(3_3)
Also, the knitting of socks for family members to keep warm was described by one participant sharing how care for keeping warm extends beyond the heating of spaces to providing the means to keep bodies warm:
And now that my grandchildren and my own child, who have been apartment dwellers until now, have experienced the increased coziness and reduced heating costs, I can see that over the past year, they’ve clearly internalised that this is a good thing. And yes, they have enough woollen socks because grandma knits them.
(2_12)
An increased reliance on solid wood in hybrid heating systems was also connected to changing heating routines linked to working from home or retirement. In some oral histories this meant a shift in heating with more use of wood-based heating due to the ability to manage the heating rhythm more flexibly. This change can be motivated by the consciousness of energy prices but also by thermal delight and enjoyment derived from wood heating:
This winter we’ve used the stove a lot more due to the electricity prices. And we both mainly work from home, so.
(1_21)
Now that I’m retired and have more time, I really enjoy heating with good, dry wood, like we have for this winter and next. Every day, I bring a basket of wood from the cellar and heat the place. It’s a nice kind of warmth. There’s a difference between that warmth and the warmth from electric heaters.
(2_13)
The attachment to and preference for keeping wood as part of heating systems also have a clear grounding in cultural attachments:
I don’t know, somehow for me, heating with wood is something deeply ingrained, and it also relates to my hiking hobbies and such, where it’s kind of a given that we get warmth by making a fire and then have the possibility to cook and such. So, I don’t know, somehow, I see it as both a cultural and a practical thing.
(3_09)
In the case of hybrid systems that include the possibility for cooking with wood as well, these activities were also actively used or seen as beneficial in the case of possible interruptions (see the previous section).
In addition, cooking with wood and heating were often stacked, e.g. the heat from the ovens simultaneously contributed to the preparation of food and the heating of spaces:
And then we have a stove, so in winter it’s used every day. Of course it provides heat for heating. Then there might be food boiling, kissel, the next day’s porridge or porridge for Karelian pies or anything. There might be three or four pots on it. So it’s quite energy-efficient to use.
(1_18)
And of course, this is combined with cooking today as well. For example, if the oven is warm, we make everything in it to save electricity since it is expensive.
(1_19)
Thermal delight provided by the access to fire has been discussed, including how even access to an open fireplace, less useful for heating, can increase preparedness, while also providing thermal delight:
Fire is, of course, beautiful to watch. That’s one thing. And also, during power outages, we’ve even made coffee in the fireplace. It’s kind of like, since we don’t have a stove, which would be quite good. A wood stove would be great for cooking. And then there’s the sound of the fire, it’s wonderful too. You can tell when it starts, even from childhood memories, you can remember exactly how it started, the sound it made that now the stove is burning steadily once it catches properly.
(1_4)
In addition to thermal delight for winter, hybrid heating systems can also provide pathways to increasing thermal comfort in summer. In the oral histories, participants also underscored the possible role of heat pumps in providing cooling:
We use the air source heat pump to keep the whole place cool in the summer, so it can be as cool as 22°C. It’s quite comfortable inside. Since there are no trees shading the house, it gets unbearably hot at night without the cooling.
(2_5)
The use of hybrid systems for both cooling and heating also comes with changing consumption patterns as well as changing expectations for indoor temperatures, particularly during summer. In addition to using hybrid systems to achieve thermal delight in the home, participants also discussed achieving thermal delight via accessing systems different to their own at a summer cottage and achieving thermal variation via the sauna, a common Finnish cultural attribute in the summer cottage but also the home, where a preference for wood-heated saunas was clear in several narratives:
Yes, but it’s really that during the summer, we haven’t needed to heat the building [the summer cottage]. So it’s been nice to be able to make a cozy fire and maybe just grill sausages or something. For an apartment dweller, it’s always a particular nice thing, the smell, the sight, everything related to a live fire.
(2_12)
At the cottage we live a bit more traditionally. When it’s cold, we light the fireplace and use the sauna every day. In everyday life, we don’t have to think about these things.
(1_26)
This preference for wood-heated saunas connects reflections on hybrid heating to both the role played by thermal delight via the expressed preference for warmth coming from a fire and environmental considerations such as the impact of one’s own consumption and the ways in which the burning of solid fuels impacts air quality. This highlights how thermal delight and ecological awareness, supported by ambitious climate policies (TEM 2019) and public campaigns focusing on energy consumption (Motiva 2023), coexist in everyday heating choices. Overall, the analysis points to the importance of everyday activities in operating and engaging with stacked modes of keeping warm.
3.3 Environment
Reducing the environmental impact of heating is a long-standing part of Finnish policymaking and an integral part of achieving carbon neutrality by 2035 (Ministry of Economic Affairs and Employment 2022). In the oral histories, when discussing the environmental impact of using multiple systems to keep warm, participants reflected on both the overall impact of their consumption and its immediate impact, particularly on air quality.
The use of multiple systems and stacking of everyday activities central in providing thermal delight comes with a need to reconsider the associated consumption patterns and their environmental impact. Participants shared how their respect for nature, fire-making skills and careful timing for maximum heating benefit guided their sparing use of firewood, illustrating a conscious effort to balance thermal delight with environmental responsibility:
First of all, you build the structure well and use the firewood as efficiently as possible, and that hasn’t disappeared yet. So that kind of saving, and somehow being at the mercy of nature when you sow crops, you’re completely at the mercy of nature. So somehow, it hasn’t disappeared either, that you respect nature in that way. So that kind of wastefulness has never been, you could say that I’m always thinking about how to get the comfort, coziness, and warmth with the smallest possible energy consumption. And in that, I’m definitely an expert.
(2_8)
And pretty much one wall’s worth of firewood is enough for the winter. We always burn just one load at a time, and that keeps the heat consistent. So, what would it be, maybe five to six cubic meters of firewood in a winter? It’s also a relatively small amount of firewood consumption if you think about it. So, in that sense, we are also economical.
(1_28)
Still, the oral histories also reflect an awareness of the direct environmental implications of using wood. Here, especially the production of fine particles stemming from burning wood were discussed:
When you burn wood, it produces fine particles. Well, it certainly does, but whether it’s […] I don’t know […] I don’t know how significant the particulate emissions from wood heating are. I can’t say, but it might […] I do understand that if you’re in the middle of a grid plan with big buildings. […] The smoke circulates there and all, but I don’t. […] In a residential area like this, it’s a bit harder to think about what sense it makes, but still.
(1_46)
But on the other hand, I’ve also been thinking about this environmental perspective, which I haven’t really delved into much or gotten definitive answers on, and I haven’t fully come to my own conclusion either. But I’ve been thinking about the balance, that small particulate emissions do come from wood heating. So, in a way, if there’s low-emission electricity available, I’m OK with paying a bit more for electric heating, which is also easier compared to wood heating. But then there would also be fewer particulate emissions drifting into the nearby areas and perhaps into the atmosphere in general.
(3_6)
The impact of hybrid systems on the environment varies throughout the year, with the use of fireplaces to supplement another heating mode happening especially in winter. While these activities enhance thermal comfort and delight, they also contribute to localised air quality concerns. One participant described this temporal pattern, noting its tangible impact on air quality:
But in this area, many people have fireplaces, and you can definitely notice it. I could imagine that there are probably some particulate emissions during the winter.
(3_9)
Participants also balanced between the use of wood for achieving warmth and thermal delight in stacked systems and their appreciation for nature and forests:
Yes, and the forests, they definitely move the soul of Finns, and if you think about it, for most of us, the forest and nature are a big part of our inner life.
(1_29b)
3.4 Difficulties in accessing stacked systems
While those participants able to access hybrid heating systems highlight the benefits for domestic heating and engage in diverse ways with hybrid systems as outlined above, not all participants were able either to develop a hybrid system or to access the same benefits. While there may be multiple reasons and restraints for not being able to access hybrid heating systems, the following section unfolds those shared by participants in the oral histories focusing on lack of impact and the financial dimension of hybrid heating.
One reason for the absence of hybrid solutions is a lack of possibilities to influence decisions about developing the heating system. Participants highlighted this especially in rental situations and when reflecting on navigating different situations and opinions on heating in a housing company.1 Interestingly, limited impact when renting was also associated with increased ease of not having to manage heating. Pondering the balancing between impact and ease, one participant shared:
So maybe it’s that, well, when you live in a rented studio apartment, you don’t really have to think about whether to buy some solar panels or set up some gadget on the balcony or something like that. But maybe you’d have to think about those things if you lived somewhere else or planned to live in, say, a detached house.
(1_34)
In addition to the possibility of influencing heating solutions in one’s home, financial constraints were discussed as hindrances in developing hybrid heating solutions. While hybrid heating can have financial benefits and increase preparedness (see the above section), participants also reflected on the financial resources needed to develop their own heating system. Although various subsidies for changing heating systems are part of policy efforts (ELY Keskus 2025) and past tax benefits targeting labour costs in the early 2000s, while not specifically designed to do so, have supported the uptake of heat pumps (Lauttamäki & Hyysalo 2019), access to these measures is not equally distributed. One participant pointed out the uneven distribution of financial means:
But then you also have to take into account that not everyone has that opportunity, so of course, here again speaks someone who has a specialist job, and well, not secure income but still always then a two-income household and so on, so of course it affects quite a lot what kind of options a person has and how much they want to invest in this kind of thing, so you have to have that kind of environmental orientation, but then you also have to have the financial means to implement those ideas.
(1_28)
Another participant emphasised that access to a hybrid heating system is not always planned or beneficial, nor does access guarantee the ability to effectively stack heating modes and reap the possible benefits such as flexibility and thermal delight. In this case, a poorly executed renovation led to insufficient insulation resulting in extreme indoor temperatures, occasionally dropping to below 0°C. Using the main heating system of direct electric heating led to high electricity bills. To counter this, dwellers increasingly relied on using solid wood, which was initially intended only as a supplementary source of heat. As they describe:
It came as a surprise that you can’t maintain the basic warmth any other way. I imagined that wood was just an extra on top of that. That it’s not necessary nowadays, that you can use it if you want. Maybe a bit naively, for the sake of ambience. I mean, if the electricity price was somehow more reasonable and it wasn’t extremely cold, then the electricity would be enough, the radiators would be enough. The house is now sufficiently well-insulated. We also changed the windows and so on, so the warmth stays in.
(3_5)
Thus, access to stacked heating modes does not automatically result in having all modes available for heating. Instead, factors beyond the available infrastructure can dictate usage patterns of heating systems that are not wished for by dwellers.
Taken together, these categories provide a holistic picture of individual experiences and motivators for stacking heating systems in the home. The reasons for appreciating hybrid heating solutions also carry with them implications for how domestic heating transitions are understood and facilitated. Table 2 summarises the key drivers and their transition implications as well as challenges in accessing stacked systems.
Table 2
Summary of the reasons for stacking and their associated difficulties.
| DESCRIPTION | TRANSITION IMPLICATIONS | |
|---|---|---|
| Reason for stacking | ||
| Preparedness |
|
|
| Thermal delight and everyday activities |
|
|
| Environment |
|
|
| Difficulties in accessing stacked systems | ||
|
| |
4. Discussion
The analysis of the oral histories highlights the diverse drivers and motivations behind the adoption and operation of hybrid heating systems. This diversity challenges how heating transitions are conceptualised and facilitated.
A key motivator for stacking heating systems is to increase preparedness in everyday life. More volatile and increasing energy prices after 2020, driven by factors such as the post-pandemic economic rebound and Russia’s invasion of Ukraine in 2022 (IEA 2025), contributed to reconsidering the need for preparedness in everyday life in the oral histories. Wood, in particular, is seen as a reliable energy source and it is used more actively. Place also is a driver for stacking diverse heating modes, especially in rural or remote areas not connected to district heating. In such settings, experiences with infrastructure damage and the connected supply interruptions are more present than in urban experiences, even though the overall security of supply of electricity is consistently high in Finland (Fingrid 2025). Self-sufficiency is not seen merely as a preference but as a necessity, with wood playing a key role in its provision. The centrality of wood is also based on the deeply embedded familiarity with operating wood-based heating systems, supporting research that highlights the importance of practical knowledge in using a heating system (Kajoskoski 2024).
Hybrid heating systems are a tangible way for households to engage with the heating transition. Yet, in the case of low-carbon options relying on the installation of new systems or technologies, they also presuppose knowledge and financial capacity on the side of citizens, including in the management of systems. Developing these capabilities for participation is key. The practical knowledge gained from operating hybrid systems can inform future solutions in Finland by building on these experiences with multimodality.
Hybrid heating also contributes to thermal delight (Heschong 1979). The stacking of fuels for reasons of attachment or thermal delight assigns a central role to wood-based solutions in hybrid arrangements. Participants highlight the importance of access to ovens, stoves or fireplaces, which were often associated with thermal delight and a cozy atmosphere, especially in colder conditions. The sauna is also central in providing thermal variation and delight to dwellers. The ability to access different forms of heating at home and at a summer cottage provided ways of accessing thermal delight by switching environments rather than changing systems at home. A deeper understanding of how hybridity and thermal delight are connected in domestic heating arrangements contributes to deepening critiques of efficiency-centric approaches (Shove 2018), highlighting that hybrid heating arrangements not only can support cost and environmental goals but also can contribute to wellbeing in the home.
Hybrid heating arrangements that include wood are also embedded in domestic activities, such as cooking, which are used to structure daily and seasonal time (Jalas & Rinkinen 2016; Rinkinen & Jalas 2017). The results point to a distinction between the stacking of heating technologies and the stacking of everyday activities. In this sense, hybrid heating can also mean that a specific activity related to heating or an established heating system is carried over into ongoing and future transitions. Additionally, specific activities can be revived in response to crises, such as volatile or high energy prices, to enhance preparedness. While these dimensions are interrelated, recognising their distinct dynamics supports a deeper understanding of hybridity in domestic heating and can, in turn, provide a valuable starting point for considering the broader implications of hybrid heating systems.
The results presented here also point to the central role of care in keeping warm. Previous research stresses that heating is a complex social phenomenon that brings with it a diversity of embedded socio-cultural aspects including care, enjoyment and an appreciation for agency in controlling domestic heating (Madsen 2018, 2025; von Platten et al. 2025). Overall, in line with previous research (Rinkinen & Jalas 2017), the oral histories point to the persistence of heating-related activities across life transitions, as dwellers take these activities and expectations of previous heating arrangements with them into new living environments.
The narratives share an awareness of the environmental implications of heating choices. While the stacking of heating modes, especially the use of solid wood, is recognised for increasing resilience and providing thermal delight, participants also reflected on environmental drawbacks, especially the impact on air quality. Still, participants also describe efficient wood use to reduce overall consumption and thus minimise their impact. Given the negative climate impact of domestic wood combustion in both rural and urban areas (Savolahti et al. 2019), a careful balance needs to be struck between accessing the benefits of wood heating and aligning everyday activities with overarching climate goals.
The results also show that stacked heating systems are not solely seen positively. For some participants, financial constraints limit access to hybrid heating solutions or control over which heating mode dominates, meaning that the benefits of hybridity are out of reach. This highlights a qualitative difference between those who stack for thermal delight and those who do so out of thermal necessity, often amid facing increased energy vulnerability and possible energy poverty. To date, energy vulnerability and energy poverty have received limited attention as distinct phenomena in Finland, often being addressed as part of a social policy (Castaño-Rosa et al. 2022; Nordic Energy Research 2024; Oja et al. 2013; Runsten et al. 2015). This touches upon broader questions of inclusion or exclusion from actively participating in domestic heating transitions. It also intersects with debates about energy consumption. A hybrid heating system can be operated out of a place of necessity prioritising the cheapest available mode. Yet, when all components are used simultaneously to achieve not only warmth but also thermal delight, hybridity can contribute to increased domestic energy consumption.
The results show that the drivers and motivators underpinning hybridity in domestic heating are more diverse than those currently dominating the policy discourse. As this research shows, domestic heating realities are not solely shaped by technological or financial concerns, but thermal delight, care and everyday activities are equally legitimate drivers shaping heating futures. Acknowledging this full spectrum of factors in designing new heating solutions and policy responses is essential for facilitating heating transitions that prioritise technological innovation and also aim to build low-carbon heating futures that take delight seriously.
5. Conclusions
This paper advances a better understanding of stacked heating systems by focusing on individual experiences that shape their use. The dataset brings together participants who shared diverse drivers for adopting hybrid heating systems. While the scope of the project and recruitment mean that the dataset is not representative of domestic heating in Finland, it offers valuable insight into the lived experiences and motivations for heating choices, contributing to a more nuanced understanding of hybridity in domestic heating.
The study frames heating transitions as complex, context-dependent processes, instead of linear technological substitutions. Rather than moving from a defined start to a targeted finish, transitions are complex and ongoing negotiations of what is phased out or phased in. The results highlight stacked systems as dynamic combinations of technologies and everyday activities. Moreover, the dominant heating mode in use is shaped by factors such as thermal delight, preparedness, flexibility, domestic routines and environmental concerns. The results also show that stacked heating is not universally accessible. Financial constraints can prevent the installation of new systems, and, in some cases, financial pressures mean that instead of operating an existing hybrid system dwellers need to rely on a single system, or to stack heating modes out of necessity rather than choice in order to maintain adequate warmth and counteract the costs of one heating mode.
While stacking offers notable benefits, it is important to consider the risk of entrenching or reverting to more carbon-intensive systems, whether for preparedness, thermal delight or domestic activities. This can lead to increased energy vulnerability, exclusion from the energy transition and higher resource consumption, even when low-carbon options are available.
The stacking of heating modes requires careful policy consideration in the context of low-carbon and resource-efficient transitions, likely also applicable beyond the Finnish context. More discussion is needed about the implications of mainly phasing in heating systems and stacking systems in homes, without also supporting a more active phase out. This dynamic calls for a rethinking of transitions to acknowledge their complexity and move beyond technology-switching.
Future research should explore how to balance the household-level benefits of hybridity, including preparedness and the continuity of cherished everyday activities, with managing negative externalities, especially when hybrid systems rely on solid wood. This is especially relevant when preparedness strategies support hybrid systems, yet these carbon-intensive systems are used mainly for thermal delight or everyday activities rather than in response to immediate crises. Acknowledging individual experiences as legitimate drivers in the design of low-carbon transitions is crucial and it suggests that new heating system innovations may be needed that respond to the importance of everyday activities and care as well as expectations of thermal delight. Finally, further research is needed to better understand the fine line between providing financial flexibility to households as opposed to having households manage increased energy vulnerability through an overreliance on carbon-intensive modes within hybrid systems.
Notes
[2] The term ‘housing company’ (Finnish: asunto-osakeyhtiö) refers to housing properties owned by tenants through a limited-liability housing company where ownership of shares provides the right of exclusive possession of an apartment or part of the building (Kiinteistöliitto—Taloyhtiö n.d.).
Acknowledgements
The work within JUSTHEAT was a collaborative effort between all team members: Aimee Ambrose (principal investigator—PI), Becky Shaw (co-PI), Sally Shahzad (co-PI), George Jiglau (PI Romania), Jenny Palm (PI Sweden), Sofie Pelsmakers (PI Finland), Kathy Davies, Sarah Kilpeläinen, Andreea Vornicu, Jenny von Platten, Anca Sinea, Raúl Castano De la Rosa, Mari-Sohvi Miettinen, Katarina Varis, Maria Olariu, Ram Krishna Ranjan, Henna Aho, Denise Lobont and Miles Umney.
Competing interests
The authors have no competing interests to declare. Sofie Pelsmakers is a member of the journal’s editorial board, but had no role in any of the editorial processes and editorial decisions for this manuscript.
Data accessibility
The data used in the study are not openly available.
Ethical approval
Ethical approval for the study was obtained following the principles outlined in the European Union’s General Data Protection Regulation (GDPR). All respondents were given a privacy notice including information on the research project and processing of their data, after which they provided informed consent.