Materials changing the performance of the household energy consumption practices

Materials are an essential part of social practices, their performance and sustainability. However, there are different views on the role of materials in practices and the agency they induce in relation to humans. The purpose of this research is to examine the agency of material in the household energy consumption practices. To this end, we analyse consumer narratives ($n\; =\; 25$) and interviews ($n\; =\; 30$) on daily home practices. Based on practice-theoretical analysis, we demonstrate that materials can change the performance of a practice in three main ways: by delaying the performance of the practice, shaping its performance, or creating a new practice. Furthermore, by comparing the material agency from human-centric and posthumanist practice theoretical approaches, we pinpoint the variability on the views on material contribution to practices and their sustainability. We show how sustainability is determined by the materiality of the practice, its connection to other practices, and people's reactions to the disruption caused by the material.

home, practice theories, household consumption, energy consumption, materiality, sustainability

Practices and their materiality play a crucial role in determining how (un)sustainably we live. As Spurling et al. (2013) argue, targeting social practices is more effective for sustainability policy than focusing solely on 'behaviour', 'choice', or technical innovation. Many everyday practices are resource-intensive and often performed unconsciously (Gram-Hanssen, 2014). Typically, we do not notice the materials involved in these practices. For example, we do not consciously consume energy; rather, we perform practices that consume energy, making it difficult to reduce environmental impact (Jack, 2022). Shove (2003b: 198) contends that much consumption impacting the environment, such as heating, is often beyond individual choice. Goods and technology influence how energy is consumed at home (Sahakian and Wilhite, 2014).

Consequently, homes play a pivotal role in transitioning to more sustainable lifestyles, as housing is a major contributor to greenhouse gas emissions (Salo et al., 2021; Tukker and Jansen, 2006). The demand for energy in domestic practices has risen over the past century significantly due to larger living spaces, higher indoor temperatures (Kuijer and Watson, 2017), and an increase in electrical devices (Jacobsen, 2019; Sahakian, 2022). Investigating practices related to energy consumption is crucial for making housing more sustainable.

The significance of materials is deeply intertwined with the performance of practices (e.g., Rinkinen et al., 2015; Sahakian et al., 2020; Shove et al., 2014). Practice theory, often seen as a response to individualistic perspectives on everyday life, focuses on the conditions surrounding the practical performance of social life (Halkier and Jensen, 2011). Material entities are considered part of practices and to surround, enable, shape and even reproduce them. Technological innovations can reveal the significance of unnoticed material objects in everyday practices (Shove et al., 2007). Practices inherently possess the potential for both stability and change (Pink, 2012), with changes occurring through the reordering of their elements (Evans et al., 2012).

As commonly noted, no single, unified practice theory exists (e.g., Halkier and Jensen, 2011; Reckwitz, 2002; Warde, 2005); instead, practices are studied through various approaches that differ in their views on the role of material in practice performance. Where some approaches assign a pivotal but still rather passive role to materialities, such as Reckwitz (2002: 250), who states that 'objects are handled' in practices, others view the material world as more agentic in the creation of practices (e.g., Gherardi, 2016). Strengers et al. (2016) define agentic capacity as the ability for entities to act in the world, an ability emerging in relation to other entities. In human-centric approaches, objects do not possess agency but act as enablers of human practices (Reckwitz, 2002; Schatzki 2001). Schatzki (2002: 192) writes that there are two types of doings and agencies.

Humans and non-humans can do things causally but only humans can perform an action, carry out a practice or embody practices. Many human doings instantiate this sort of agency. In contrast, in posthuman practice theory, agency is an outcome of the relationship between artefacts and humans (e.g., Pickering, 1995). For instance, Jones and Boivin (2010: 346) define agency as the ‘material qualities of things and their involvement in social practices’, advocating for greater symmetry between humans and non-humans.

This study focuses on household energy consumption practices. Our aim is to explore the implications of materials in the change of home practices to better understand the agency of houses, systems, technologies, and other material entities (Rinkinen and Jalas, 2017). We ask how materials change the performance of household energy consumption practices and how they contribute to sustainability. We approach the role of materials in practices from different practice-theoretical perspectives, thus gaining a multifaceted understanding of the role of materials in the sustainability of practices. Subsequently, we shed light on how materiality is understood in various practice-theoretical approaches within the consumption literature, complementing this body of research by analysing our empirical material from human-centric and posthuman perspectives to highlight their variations. Previously, Rinkinen et al. (2015) have investigated object relations, and Madsen (2018) has studied heating and cooling technologies change heating and cooling practices. In our research, we focus on the influence of materials on the human world, thereby adding to Madsen’s (2018) work. In this way, our study contributes to a more nuanced understanding of the roles assigned to materials in various practice-theoretical approaches. Further, our findings promote understanding of the role of materials in the sustainability of home practices, emphasising the importance of recognising how consumption occurs to support sustainable lifestyles.

According to many practice researchers, materiality is integral to the social world, shaping and reproducing practices. Material things’ social significance lies in how they are handled (Reckwitz, 2002), mobilized in practice, and combined in practice-arrangement nexuses (Schatzki, 2010). The lives of things and practices are mutually co-constituted and densely interwoven (Reckwitz, 2002; Shove, 2016). Nevertheless, there is no consensus on whether materials merely mediate activity, serve as intermediaries among humans, or act as carriers of practice.

We present different approaches to materiality in practices, forming a continuum rather than distinct categories (see Table 1). We aim not to provide an exhaustive conceptualisation of extant practice theoretical approaches, but rather to select sufficiently diverse perspectives to enable discussions on different ways of understanding the agency of materials. We focus on approaches used in consumption research, especially in domestic contexts. In the following table, we identify these approaches as human-centric, co-humanist, and posthumanist. We discuss the typical concepts used in each, the viewpoint of agentic capabilities, key theorists, and related key references in housing research. The agentic capabilities describe how each of the approaches regards the possibilities of materials to influence the performance of practices.

The human-centric practice theory considers materials as enablers of human practices. This approach relies heavily on Schatzki, who posits that 'human coexistence transpires as arrangements of people, artifacts, organisms, and things' (2002: 149). As this approach regards practices as human practices, and agency assigned to humans, with non-human materials playing a significant role in enabling humans to perform these practices, we term this a human-centric approach to practice theory. According to Schatzki (2010), materiality is a part of society, but material things are not part of practices; instead, materials form arrangements co-produced with practices (ibid.: 135). Materiality is defined by Schatzki (2019: 53) as a physical-chemical composition of entities. Material entities are connected to human actions; they are determinants of continuity and longevity in practices, mediating and enabling practices and exerting causal effects (Schatzki, 2010). This means that material arrangements prefigure human practices.

This perspective is visible in Bariaux et al.'s (2014) study on energy retrofits, where technologies and products are components of practices performed by people. Although material arrangements may hold meaning for non-humans, material arrangements remain practices in which humans engage (Schatzki, 2010). This perspective implies that only humans are carriers of practices, and non-humans, whether living or not, are mere objects supporting, anchoring, inducing and prefiguring human practices. However, human bodies are also matter. Social practices are internalized in humans' bodies and minds, so the practices are embodied and thus visible in people's actions (Bourdieu, 1977). The practices are therefore strongly linked to the physical essence and materiality.

The co-humanist approach views material things as elements within practices, distributing agencies and competences between things and people (Shove et al., 2012: 113). Although this approach draws on ideas from science and technology studies, this perspective stops short of accepting Latour's claim that 'artefacts can have a capacity to construct social order' (2000: 113). Instead, Shove (2003b: 12–13) highlights the embedding of ways of life within tools, devices, and material objects. She emphasises the mutual shaping of technologies and their users, as well as the potentially formative role of things and sociotechnical systems. In consumption research related to housing, a co-humanist perspective is evident in studies such as those by Holmes et al. (2022), Rinkinen et al. (2015), Sahakian and Wilhite (2014), Shove et al. (2014), and Spurling (2021). To illustrate, Holmes et al.'s (2022) study demonstrates how, during the lockdown, when all activities took place at home, the form and function of materials became changeable. For example, furniture or home spaces acquired new uses.

More specifically, Shove (2016) categorises material things into three different roles that show how co-humanist approach assigns only limited agency to materials in the practices with materials having varying impacts on practices. She claims that 'materials are defined, constituted and positioned with respect to each other through their role within specific practices' (p. 157). Things can possess an infrastructural relation to practice, which means that these things are necessary, but they are not interacted with directly. Rather, they form the background to the practice. In the context of housing, this background can be, for example, the home or kitchen, or, more broadly, the infrastructure that also enables living. Second, things can be mobilised or manipulated, or in other words they play a device-oriented role in relation to the performance of a practice. Third, things

can be used up or radically transformed. Clear examples are resources or products that eventually become waste: they are used, and their form is altered. Notably, the same object can play different roles at different times.

The posthumanist approach posits that material things play a more agentic role in the social world, forming practices through the actions of both material entities and humans (Pickering, 1995). Posthumanism decentralizes the human as the master, acknowledging the agency of multiple others and highlighting the entanglement of all earthly creatures (Valtonen et al., 2020). Matter is recognized as “an active participant in the world’s becoming” (Barad, 2003: 803). Matter actively participates in social processes and extends human activity in space and time (Monteiro and Nicolini, 2015). For example, Bäckman’s (2023) study shows how materials in the home, like a showerhead, can encourage greater consumption than might have been intended. Kuijer (2018) argues that with washing machines performing tasks that humans previously did, agency has become shared. Similarly, Strengers et al. (2016) indicate that animals also consume energy.

The concept of sociomateriality is integral to posthumanist practice theory, asserting that the social and the material are co-constituted, and nature and culture are entangled (Gherardi, 2016). Fuentes (2014: 108) defines the sociomaterial in posthumanism as treating materiality – including meanings, images, things, humans, and non-humans – as simultaneously and intrinsically interlinked.

In sum, while human-centric practice theory focuses on humans with their embodied understandings and practices, posthumanist theory questions how all elements within a practice hold together and achieve agency through entanglement (Gherardi, 2016). Posthumanists consider that humans and non-humans share agentic capacities. In our empirical analysis, we explore household energy consumption practices from the human-centric and posthumanist perspectives to highlight the variability in understanding material agency.

In this study, we analyse qualitative data consisting of written narrative diaries and interviews to understand the influence of materials on the performance of practices. Previous research has employed interviews (e.g., Gram-Hanssen, 2010; Rinkinen and Jalas, 2017) and consumer diaries (e.g., Rinkinen et al., 2015) to study domestic consumption using a practice-theoretical approach. Diaries are useful for understanding practices as they reflect the variety of symbolic resources and societal discourses their writers engage with (Atkinson and Coffey, 2003; Halkier and Jensen, 2011: 109). Since diaries can capture small details (De Certeau, 1984) and interviews allow for open-ended questions, we use both methods to enhance our understanding of consumers’ daily lives (Halkier and Jensen, 2011).

Participants were recruited via a pre-questionnaire shared on social media, with 79 Finnish consumers expressing interest. Of these, 25 completed narrative diaries and 30 were interviewed. Both diaries and interviews were collected during COVID-19, likely increasing the time spent at home and attention paid to domestic environments.

Diaries were collected in Spring 2021, with participants aged 31 to 65 (average age 46); 23 identified as female and two as male. Participants described everyday moments of

home usage, guided by questions on the elements of practices and involved entities. Similar to Bartiaux et al. (2014), we chose to focus on the practice-theoretical elements of procedures, understandings, and engagements (Warde, 2005) as well as social interaction, materials, and non-human entities, to enable the emergence of both elements of practices and the non-humans participating in the actualisation of those practices. The data included activities like heating, water consumption, ventilation, recycling, and home maintenance. The data comprises 46 pages of diverse diary entries.

Interviews were conducted in Autumn 2021, with participants aged 30 to 73 (average age 49); 26 females and four males. Fourteen interviewees also completed diaries. Interviews covered housing aspects like housing solutions, practices, sustainability, dreams, and future visions. The diary data was thematically pre-analysed before finalising the interview guide to deepen the discussion related to the most pivotal energy consumption-related topics. Thus, the interview theme on practices, was created according to the most common topics in diaries: temperature regulation, home maintenance, and water consumption. The texts of those interview participants who had written a diary were used in the interviews during the theme on practices to refresh their memory. This approach allowed the participants to elaborate on specific situations from their diaries in their own words. For those who had not written a diary, a parallel method was employed. They were encouraged to reflect on events or routines related to temperature regulation, home maintenance, and water consumption, enabling them to share their experiences in a similar manner.

Interviews lasted 22 to 111 minutes (average 46), producing 256 pages of transcribed text, along with home photographs and observation notes. Sixteen interviews were conducted in participants' homes and 14 remotely via Zoom or Teams. When the interview was conducted in the participant's home, the participant gave a tour of their dwelling while discussing with the researchers on household appliances, systems, and other materials, and researchers taking pictures of the participants' homes. In the remote interviews, the participants were requested either to walk around their homes while taking video footage or to verbally describe their home.

The narratives and interviews were analysed simultaneously through a multiphase process. Initially, a data-driven approach was employed by reading diaries, transcribing interviews, and reviewing recordings. The first analysis round focused on identifying various materials involved in home practices. According to Haraway (2003), entities and categories are fluid; they can embody multiple roles simultaneously as materiality, meanings, and boundaries evolve continuously. We sought to understand different materials and their roles in practices, inspired by object interviews (Holmes, 2020), examining the significance of various materials and their structuring of practices. Non-human materials' impact became particularly clear when practices deviated from expected outcomes, highlighting materiality's influence.

In the second analysis round, data sections identifying materials' influence on practices were systematically reviewed, revealing three ways materials change practice performance. In the final analysis round, we employed a theory-driven interpretation, analysing

these influences through different practice-theoretical approaches to materiality (Table 1). We selected data excerpts to demonstrate the variations between human-centric and posthumanist perspectives on materiality. We focused on the extremes of these perspectives to highlight their differences clearly.

Our analysis focuses on what materials are like, what they do when the practice is performed, and how the role of a material emerges in relation to other materials. Based on our analysis, a variety of materials can change the performance of the practice in various ways, thus highlighting the agency of materials in the performance of practices: the material can delay the timing of practice performance, it can shape how practice is performed, and material can also create a new practice. Next, we analyse these different changes using human-centric and posthumanist practice-theoretical approaches to materials.

This study addressed implications of materials in the change of the performance of household energy consumption practices. Materials are an essential part of social practices and their performance (e.g., Madsen 2018; Reckwitz, 2002; Rinkinen et al., 2015; Sahakian et al., 2020; Shove et al., 2012), and they may even influence the very existence of these practices. Recognising the constant relations among people, beings, and things facilitates a better understanding of energy consumption (Butler et al., 2016) and energy demand (e.g., Rinkinen et al., 2020). Consequently, research on domestic practices has increasingly emphasised the role of materials (e.g., Hand et al., 2005; Rinkinen et al., 2015; Sahakian et al., 2020; Shove et al., 2014; Spurling 2021). Our study contributes to this discussion by (1) demonstrating how materials provoke changes in practices and by (2) highlighting different interpretations of material agency from various practice-theoretical perspectives.

Based on our qualitative analysis, materials such as home appliances, systems, weather, and the house itself affect home practices in various ways: they can delay, shape, or create new practices. We examined the relations between materials and people from two perspectives: human-centric and posthumanist. This analysis aimed to highlight how a change in the perspective can reveal insights into the involvement of non-humans in carrying out practices. In posthumanism, non-human entities gain agency in the performance of practices, whereas in the human-centric view, materials merely intervene in human action. Thus, the current study contributes to existing theory on the role of materials in energy consumption practices (e.g., Sahakian et al., 2020; Shove et al., 2014). Although the human-centric approach to practice theory emphasises humans as carriers of

practices, through this lens material may still be influential in changing practices as materials participate in enabling the practical performance of everyday lives (Schatzki, 2002, 2010). To illustrate, the functioning of a heat pump may change when and how the practice of showering occurs. The posthumanist approach to practice theory focuses on the agentic capacities of material entities in relation to other entities; thus, from this perspective, they are not simply enablers of human practices but may even perform practices themselves (Gherardi, 2016). For instance, a ventilation system may be regarded as carrying out the ventilation practice.

To reduce energy consumption and emissions, understanding how home practices are changed by materials is essential. Regardless of the approach to practice theory, humans' agency in performing social practices is always somewhat tied to non-humans. For instance, water and indoor air consumption involves technology and automation that use energy and water. Our analysis revealed how poorly functioning ventilation or water-related devices can increase overall consumption, highlighting the interlocking of materials and practices and their impact on sustainability (Foulds et al., 2013).

When new technology is introduced, it disrupts practices, providing an opportunity to change routines. Recognizing these disruptions is crucial for sustainability. The sustainability of a practice may be influenced by the materiality of the practice, i.e., non-human materials. Humans also play a role in how sustainability is realised, as their reactions are also a determining factor. Humans can react to influence in multiple ways, and this reaction can affect the sustainability of the practice in question. In particular, the desired level of bodily comfort may influence this reaction, for example as the adaptation to heatwaves is becoming increasingly topical. Comfort may play an essential part in the home and cleanliness practices (Shove, 2003b) and explains why current practices are unsustainable.

The value of our study and our use of two practice-theoretical perspectives in the analysis of mundane household energy consumption situations is that it allows the identification of focal points where material relations might require special attention in order to improve the sustainability of housing. Our study suggests that attention could be directed at (1) human engagement, such as action motivated by irritation at material arrangements that fail to facilitate practices in an optimal way. In addition, it is important to (2) consider the connections between practices and (3) whether material entities collaborate smoothly with other entities. In all, consideration could be given to whether materials function as intended as part of practices.

As the significance of materials is intrinsically entwined with the performance of practices (e.g., Rinkinen et al., 2015; Sahakian et al., 2020; Shove et al., 2014), the materiality intertwined with practices is crucial in determining how (un)sustainably we live. In this study, we have explored the implications of materials in the change of home practices to better understand the agency of houses, systems, technologies, and other material entities. The findings of this study show that materials may change performance of practices in three ways: by delaying when the practice is performed, by shaping how the practice is performed, and by creating a new practice.

To further analyse the different interpretations of the agency of materials in the changing practices, we examined from two different practice-theoretical approaches to the role of materials in the performance of practices to highlight their implications for the sustainability of these practices. According to our analysis, sustainability is determined by the materiality of the practice, its connection to other practices, and people's reactions to the disruption caused by the material.

Our practice-theoretical reading emphasises how the same situations can be interpreted from several different perspectives, highlighting both differences and similarities among these viewpoints. In our study of materiality, we have focused on a small unit within the economy, namely the household. However, materiality could also be connected to the broader economy (Evans, 2020), where the effects of material within the household could be seen as part of larger political, economic, and material influences on households.

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the 10.13039/501100009047; Strategic Research Council; 358275, 10.13039/501100009047; Strategic Research Council; 358343.

Sara-Ellen Laitinen https://orcid.org/0000-0002-0773-7262

Henna Syrjälä https://orcid.org/0000-0002-1076-1108

Eliisa Kylkilahti https://orcid.org/0000-0003-0116-224X

Liisa Kääntä https://orcid.org/0000-0003-2165-7100

Sara-Ellen Laitinen (M.Sc. in Consumer Economics) is a Doctoral Researcher at the Department of Economics and Management, University of Helsinki, Finland. Her doctoral research focuses on consumer agency in performing sustainable home practices.

Her wider interests include everyday practices, sustainable lifestyles, the history of consumption, and material culture.

Henna Syrjälä (D.Sc.) works as an Associate Professor (tenure track) of Marketing at the University of Vaasa, Finland. Her research revolves around cultural consumer marketing and Transformative Consumer Research, focus areas including everyday practices, spaces of consumption, post-humanism, gamification, and consumer communities. She has published in, e.g. Journal of Business Research, Marketing Theory, Journal of Consumer Culture and Games and Culture and edited collections of Seven Deadly Sins in Consumption and Multifaceted Autoethnography.

Eliisa Kylkilahti (D.Sc., Docent, Consumer Studies) is a University Lecturer at the Department of Economics and Management, University of Helsinki, Finland. Her research interests include socio-economic sustainability of consumption, climate-wise innovations, everyday life at home and cultural change, especially among young people. Currently, she conducts consumer research in a Strategic Research Council Finland funded project 'Decarbon-Home: Citizens as agents of change in decarbonizing suburban and rural housing'.

Liisa Kääntä (PhD) is a University Teacher at the Language Centre and a Researcher in Communication Studies at the University of Vaasa, Finland. She has studied institutional and mundane online discussions, as well as technologized workplace interaction and training. Her recent work includes research on media discourses and public discussions of climate-wise housing, sustainability, and responsibility.