Achieving Net Zero: How Could User Feedback Be Leveraged to Promote Domestic Heat Pump Adoption in Scotland?

Abstract

Currently, 81% of Scottish households rely on mains gas for heating, contributing significantly to the country’s carbon emissions. Although heat pumps are a central component of the Scottish Government’s transition strategy, the adoption rate has fallen short of expectations. This small-scale research study delves into the pressing issue of transitioning Scotland’s homes to low-zero carbon heating systems, a critical step in achieving the nation’s net-zero target by 2045. This study’s primary objective was to investigate Scottish homeowners’ attitudes and motivations surrounding heat pump adoption. It scrutinises homeowners’ decision-making processes, the factors influencing their choices, and the experiences of those who have already embraced a domestic heat pump as their primary heating source. Furthermore, this research aims to harness this user feedback to bridge information gaps, address perceived barriers, and promote the wider acceptance of heat pump technologies. Data were collected through a structured online questionnaire completed by a targeted sample of 61 Scottish homeowners who had already made the switch to heat pumps. The findings indicate that more targeted information and awareness campaigns can best help facilitate the widespread dissemination of heat pumps in Scotland, and that these should sit alongside support for current adopters. In doing so, it will be possible to ensure that the benefits of heat pumps are realised and that such benefits can be communicated to future users.

1. Introduction

With approximately 40% of the country’s total carbon emissions coming from the housing sector, transitioning many of Scotland’s homes to low- or zero-carbon heating systems is essential to meeting the net-zero target by 2045 [1]. Currently, 81% of Scottish homes use mains gas as their primary heating fuel [2]. Whilst there are various low-carbon heating systems available, such as those using solar and biomass energy, heat pumps have featured heavily in government transition policies and initiatives, including Scotland’s Heat in Buildings Strategy [3].

As alternative domestic heating systems, heat pumps work by taking the residual warmth from either the air (air-source heat pumps) or ground (ground-source heat pumps) and transferring it inside the property. Whilst water and solar absorption heat pumps are available, these are less commonly installed in domestic settings [4]. As the amount of heat provided is greater than the electricity required to run the system, heat pumps are more efficient than other heating systems [5]. Other advantages commonly highlighted are their lower running costs, lower maintenance requirements, and life span of 15–20 years [6]. However, their uptake is low, with the UK being one of the poorest performers in Europe in terms of heat pump adoption [7]. Of course, it is important to understand the wider infrastructural implications should this technology become widely adopted, including the demand for peak electricity and the need to ensure that heat pumps do not lead to greater levels of carbon intensity (as discussed and documented in [8]). The background literature reviewed in this study, as presented in Section 3, extends globally and tends to emphasise that issues relating to geography, the energy grid, sources of electricity, and carbon reduction can impact regional decision-making.

Whilst substantive information regarding the positive aspects of heat pump adoption is available to consumers, gathering such information usually requires extensive searching on the homeowner’s behalf. In comparison, multiple journalistic articles have been published recently focusing on the negative aspects of heat pump technologies [9,10].

The Energy and Climate Change Directorate [11] noted that data are limited regarding the exact number of domestic heat pumps currently installed in Scotland. Available data suggest that approximately 262,000 (10%) of homes do have a low-carbon heating system. However, this figure includes both heat pumps and electric storage heaters [12]. Research conducted by Bowes [13] estimated that between 517,000 and 717,000 domestic properties will be required to install heat pumps to meet the climate targets. This figure seems untenable considering only 3000–4000 domestic heat pumps are installed in Scotland annually [14].

The next section of this paper establishes the research aim and sets this within the context of previous studies in the literature. This is followed by a description of the methodology and results, and the paper concludes with a discussion of the main emerging points.

2. Research Aim

Although numerous studies have been conducted regarding homeowner attitudes and barriers to entry regarding heat pumps, this has primarily been United Kingdom-centric, and it has been noted [15] that evidence from Scotland is lacking. Furthermore, the Department for Business, Energy, and Industrial Strategy (BEIS) (2021) highlighted a need for more research linking quantitative and qualitative data with a focus on gathering feedback from customers relating to the ease of heat pump use. Potential barriers, challenges, and consumer expectations may vary by region and should therefore be addressed by region-specific information. For example, Scotland’s climate varies from that of the rest of the UK: the average temperature can be 10 °C cooler than the south of England [16]. With 44% of those in Scotland saying that they would prefer to install a heating system that they knew other people had, gathering feedback from early adopters of heat pumps and using this to tailor the focus of awareness campaigns could be key to surmounting perceived barriers and increasing the appeal and adoption of heat pump technologies within this country [17].

This research study aims to explore the attitudes and motivations of Scottish homeowners that own a heat pump system, as well as the process that they undertook to research, choose, and adopt their renewable heating system. Additionally, this research study aims to identify how this user feedback could be utilised to address campaign and knowledge voids, subdue perceived barriers, and make heat pump adoption more appealing and widespread in Scotland.

3. Literature Review

Numerous studies concerning the barriers preventing heat pump adoption have been conducted worldwide, with a consistency of findings across regions. The identified barriers to adoption generally fall into one of four categories: awareness, financial issues, suitability, or knowledge [18]. Indeed, the factor of low public awareness affecting the uptake rates of heat pumps is key. The fact is that householders simply cannot install technology they are not aware of [19]. Despite the general awareness of heat pumps increasing in recent years among the wider population, it is still trailing behind other energy-efficient options such as solar panels [20].

Biannual research is undertaken by the Department for Business, Energy, and Industrial Strategy (BEIS) into public attitudes towards heat and energy within the home. Their most recent survey [21] found that public awareness levels of domestic heat pumps had increased significantly between the winter of 2021 and the winter of 2022, increasing from 50% to over 65% of respondents; however, these figures remain low compared to other renewable technologies. A similar study focusing on heat pump awareness conducted by Home Energy Scotland [22] found whilst 51% of the 1000 Scottish respondents were aware of heat pump technologies, only 20% were likely to install them. This is in keeping with the results of the UK Government Public Attitudes Tracker Survey Winter 2022, which found that only 20% of respondents were likely to install any type of heat pump within their property, the same percentage as that found in the Winter 2021 survey [21]. Whilst this shows that awareness levels are increasing, no further exploration was conducted in either research study into the reasons behind the lack of interest in installing these technologies. It could be argued the topical focus of current awareness campaigns within the UK may be misguided as the number of householders intending to adopt heat pumps has remained the same.

3.1. User Perception of the Technology

It has long been reported [23] that consumers most frequently desire independent information relating to the performance of different heat pump systems, with many respondents mentioning that they do not wish to rely on manufacturers’ claimed performance figures, which are usually based on laboratory findings rather than real-life case studies. A subsequent study [24] into the motivations and barriers of 291 heat pump adopters, considerers, and rejecters concluded that, despite previous government efforts, the difficulty for consumers in accessing trustworthy information was a major impediment to microgeneration uptake within the UK. This was a view echoed by BEAMA [18], who recommended improving customer awareness through more trusted advice for better uptake. Recent work [25] has also stressed the importance of “intermediaries” between householders and the technological options and solutions.

These studies fail to establish what is considered a trusted source or trustworthy information; however, the BEIS [21] did ask respondents who they would trust for advice on replacing their heating system, with 42% of the public respondents saying that they would trust advice given by Gov.uk (although it should be noted that a government department commissioned this survey, so it could be argued those likely to participate would be those more likely to trust government sources). This research also found that 41% of respondents would trust tradespeople for advice, 31% said energy advice websites would be a trusted source of information, and almost a quarter of respondents said they would trust the advice given by family/friends.

Various case studies regarding heat pump installations and homeowner attitudes towards the installation process have been compiled by the Green Homes Network (GHN), part of Home Energy Scotland (HES). Homeowners can contact adopters of their chosen technologies within their area and arrange to visit their properties to talk through their experience. However, Holland et al. [26] (quoting the BEIS Public Attitudes Tracker from December 2020) noted that only 22% of consumers would trust the Energy Savings Advice Service or HES to guide the installation of alternative heating systems, despite these agencies offering free and impartial advice. This further highlights the lack of confidence consumers have in these alternative technologies, and therefore it is likely that consumers would be wary of these case study participants and question the neutrality of the information they provide.

The number of people who considered themselves to have a lot or a fair amount of knowledge regarding heat pump systems, rather than just knowing they exist, actually decreased from 20% in 2021 to 18% in 2022 [21]. This indicates that current awareness campaigns within the UK are lacking in providing in-depth knowledge to homeowners about these heating systems.

Gillich [27] ascribed unsuccessful attempts to increase customer adoption rates to the lack of cohesive messaging being presented to consumers. Likewise, Heiskanen et al. [28] noted that such failures may lead to hesitation regarding the ability to change consumer attitudes and behaviours surrounding low-carbon technologies. To explore these hesitations, the authors of [29] conducted research into the role of policy awareness in heat pump adoption within Canada and found that marketing policies needed to focus on improving customer confidence in the technologies and how effective they are in heating and/or cooling properties.

3.2. The Role of Peer Recommendations

It has been suggested by previous studies that late adopters are more likely to be sceptical of innovation [30]. Numerous ways to overcome this scepticism have been theorised, including the suggestion that information sourced from peers, rather than mass media, could increase the likelihood of adoption [31].

As shown in Finland, it is possible to change consumer perceptions and create a widespread heat pump transition. This successful conversion was largely attributed to online user-led discussion forums that allowed communication about sizing, cost, and installation [32]. Similar open-source initiatives are available worldwide, providing users the opportunity to share information about their property, their heating system, and their heating system’s annual performance, one such UK example being “HeatpumpMonitor.org”. Although the participation numbers of these sites are small (only 47 properties for the aforementioned website), they demonstrate a potential consumer preference for peer-to-peer information. Of course, it is likely that many visiting such specialised forums would already be aware of heat pumps and already be considering the adoption of such technologies. Similarly, Hyysalo, Juntunen, and Martiskainen [33] stress the importance of peer communities, whether in-person or internet-based, as serving an important function in aiding both users and potential adoptees during all stages of the transition to heat pumps. Karytsas [34] also concluded that the adoption of heat pump technologies amongst Greek householders was more likely if the respondent personally knew someone who already had the technology installed.

The Sustainable Energy Authority of Ireland [35] notes that consumers rely on the recommendations of peers to assess the value, risk potential, and quality of heating systems before purchase. The role of these word-of-mouth recommendations was of particular interest to Caiger-Smith and Anaam [15], whose evidence-based review into Scottish awareness among the public concluded that establishing an understanding of how social factors influence consumers may facilitate the identification of better routes to encourage adoption, rather than changes to policy or further incentives.

3.3. Installation of Heat Pumps and the Associated Issues for Consumers

The practicalities of installation and the additional works that may be required before adoption, such as increasing insulation levels or changing pipework, have been cited as stunting the uptake of heat pump technologies, despite financial incentives being available [36,37]. These conclusions reiterate the findings established by Caird and Roy [38]. Consumers who took part in their UK-based mixed-methods study cited that the potential disruption and difficulty of installation acted as a significant barrier to heat pump adoption. Similar to the variability of adopters’ trust, acceptable levels of disruption may be individual among adopters and therefore more difficult to quantify and to overcome. However, it could be argued that this consumer trepidation could potentially be alleviated by providing information tailored to individual property types, locations, and/or domestic heating needs.

A further study [39] into the drivers and barriers of homeowner decisions to switch to a renewable heating system found that the perceived difficulty of adapting to the system and misunderstanding of its principal functions were key obstacles for German householders when considering transitioning to a heat pump. This research also found that experts in Germany would dissuade potential consumers from installing heat pumps due to the disruption that would be caused, noting that to guarantee optimal performance, major retrofit measures or adjustments to the current heating infrastructure would be required. As stated by Ahmad ([40] as part of the UK Collaborative Centre for Housing Evidence report, to enable a successful scaling-up of heat pump adoption within the UK, end users need to feel fully informed and understanding of their choice, the associated costs, the expected comfort levels, the potential disruption, and the workings of the overall control system.

3.4. Customer Expectations

Research conducted by Burns, Strachan, and Clark [41] into heat pump use within Scotland highlighted the challenge of maintaining customer expectations, noting the potential benefits of providing information and support throughout the consumer journey, not just at the initial consideration stage. Additionally, 80% of heat pump users surveyed by Caird, Roy, and Potter [42] were satisfied with their system; however, it was noted that the main source of dissatisfaction for 22% of respondents was the quality of technical support offered post adoption. Further, it has been argued that direct mutual conversations with end users could create more personal outreach to consumers as opposed to traditional awareness campaigns, consequently leading to a more continuous transformation of heating systems within the UK [27]. This is a theory shared by Corbett et al. [29], who advocate for using behaviourally informed “nudging” through sharing consumer testimonials to increase adoption rates. However, as discussed above, these personal outreach programmes may be more impactful if organised independently from companies such as HES.

3.5. Financial and Policy Incentives

The upfront capital investment is widely considered the largest barrier to heat pump adoption. Michelsen and Madlener [43] concluded that the decisive drivers of renewable technology adoption within the German household sector were investment costs and returns. This is echoed by Jacksohn et al. [44], whose more recent assessment found economic factors to be the main driver of German householder decisions to invest in and adopt microgeneration systems, with environmental concern and housing characteristics having less relevance to adopters.

As economic factors are considered a key barrier to investment, it has been argued that reasonable incentives should be provided to combat the higher upfront costs and to steer households towards microgeneration technologies over fossil-fuel-based alternatives [44]. With regard to Scotland, government grants and loan schemes have been available to aid the adoption of energy-efficient heating systems, including heat pumps. In 2020, GBP 4.5 million was available to Scottish homeowners to be distributed as cashback grants for the purchase and installation of renewable heating systems, with individuals receiving up to GBP 7500 [45].

So far, this renewable heating scheme has failed to significantly improve the uptake of such heating systems [46]. Whilst this corroborates the studies that suggest cost motivators alone are unlikely to change the uptake rates, the low uptake rates of these grants could also be attributed to the conditions attached to the funding. These include providing an energy report recommending the system to be installed, rating and reviewing the installer on the Energy Savings Trust website, and also using a Microgeneration Certification Scheme (MCS)-certified installer [47]. This final condition could be especially problematic for those in less populated areas: for example, there are only three certified installers on the Shetland Islands, and only one installer on the Isle of Harris [48].

3.6. Property Suitability

Property type and suitability could pose a difficult challenge to overcome for the widespread adoption of heat pumps within Scotland. A study conducted by Mills and Schleich [49] concerning the adoption of residential solar thermal technologies in Germany concluded that property characteristics and geographical suitability were the factors most likely to influence adoptees of heat pump systems. Over 70% of Scotland’s housing stock has an EPC rating of C or D, whilst 28% is made up of older pre-1914 tenement flats [26], although recent research [50] has drawn attention to the over-estimation of “actual” as opposed to predicted energy use in homes rated with an EPC of C of worse. Previous research also found that households in older properties were less willing to adopt heat pumps [29].

Whilst Frontier Economics [51] suggested only advocating for heat pump installation in properties with high energy efficiency, the technology can be harnessed in all types of dwellings, regardless of their age. However, one analysis study researching the suitability of Scottish properties for air- and ground-source heat pumps [26] concluded that in a pre-1914 flat, improving insulation levels would greatly improve the system efficiency throughout winter. This would require significant additional work, time, and capital investment for homeowners.

Many researchers argue that property location is less of a key factor than how much a property may need to be adapted to overcome any limitations of the new heating system. It has been noted [52] that a property location’s climate can impact the performance of specific energy measures such as heat pumps, and therefore influence homeowners’ propensity to adopt these technologies. A study reviewing heat pump systems in Lithuania [53] recommended using air-source heat pumps as a secondary heating source in cold climates rather than the primary or singular domestic heating system. Lithuania’s temperature zone is like Scotland’s, with both countries being approximately the same distance from the equator. However, the findings of this study may not be entirely applicable to heat pumps within Scotland as Lithuania experiences more temperature extremes compared to Scotland [54].

In total, 98% of Scotland’s land mass is considered rural, and almost 20% of the country’s population was recorded to be residing in these rural locations in 2021 [55]. Rural properties are often older, more poorly insulated, and use alternative fuels to gas for domestic heating, such as electricity, oil, and LPG. This is corroborated by the Scottish Household Condition Survey 2021, which found that 72% of rural dwellings had an EPC rating of D or below, and 80% had an Environmental Impact Rating of D or below [56]. Whilst there are only 423,000 dwellings in rural locations, compared to the 2.106 million in urban areas, overlooking these properties could have a considerable impact on achieving the net zero targets, especially considering that these properties will likely have the space required to accommodate a heat pump [56]. The elevated levels of fuel poverty occurring within these rural areas means that the transition to renewables, and the associated costs, has a significant impact on these communities more so than those in urban areas [57]. Whilst the Scottish Government have implemented a GBP 1500 “rural uplift” cashback scheme providing heat pump installation grants for those in “remote rural and island” areas, with the current uncertainty surrounding fuel prices, this may not be enough to encourage heat pump adoption to homeowners in these rural locations [47].

Concerning how consumer awareness can be improved, various sources have offered their recommendations. A 70-question survey investigating the public response to the draft Heat in Buildings Strategy conducted by the Scottish Government highlighted the need for bespoke advice tailored to individual properties, with particular importance on providing reliable and realistic information concerning the performance, running, and maintenance of alternative heating systems [3]. This is a recommendation echoed by Holland et al. [26], who advise that particular emphasis should be placed on providing trusted information on what interventions may be required for individual properties to become ready for heat pump installation.

3.7. Diffusion of Innovation

It should be noted, however, that every potential adopter of these technologies is unique. One of the most discussed theories regarding various categories of adopters was established by Rogers [30], who suggests that adopters will fall into one of five groups based on how innovative they are (innovators; early adopters; early majority; late majority; laggards). Each of these groups of adopters has differing characteristics, including the level of risk they are comfortable with, the level of respect they receive within their social system, and their willingness to persist when dealing with challenges. Considering the sparse number of heat pump adoptions within Scotland, current heat pump adopters would still fall within the innovator phase—they are more willing to take a risk and persevere if presented with a challenge, but they are less respected by other adopters as they are seen as too experimental and risk-tolerant.

Rogers’ theory, known as the Diffusion of Innovations, and how the various categories of adopters understand and experience various renewable technologies, including heat pumps, has been the subject of numerous research studies. One choice experiment [31] produced results that supported Rogers’ theory, finding that Italian householder system choices can be influenced by their individual inclination to accept innovations. The results of an empirical investigation of Swedish adopters of solar photovoltaics [58] add to this conclusion, indicating that motives change for the differing categories. As such, they recommend adapting information to suit these changing motivations as it will aid new user divisions in gaining interest in innovative technologies. However, after interviewing fifteen UK owner-occupiers who use heat pumps, six installers, and five industry experts, Cretu and Zanetti [59] recommend focusing solely on smoothing the experience for these innovators as they pave the way for those coming after. They also advise trying to make information more relevant, easier to digest, and accessible to all.

As an alternative to Rogers’ theory, Michelsen and Madlener [60] proposed three distinct adopter types: convenience-orientated, more concerned with the comfort and suitability of the heating system; consequence-orientated, driven by short-term financial costs and benefits and longer-term environmental protection; and multilaterally motivated adopters, who consider a variety of aspects when making decisions. Their German-based research study into the diffusion of residential renewable heating systems concluded that those in the last group, the multilaterally motivated, are more likely to choose a heat pump system. This highlights how the focus should potentially shift from single aspects of the decision-making process, such as the environmental benefits of transitioning to a low-carbon heating system, to an all-encompassing awareness campaign highlighting all aspects of the system, including its uses, benefits, and limitations.

4. Material and Methods

The main aim of this cross-sectional research study was to discover differing attitudes of Scottish homeowners concerning heat pump technologies in order to provide a greater understanding of the key motivating factors and concerns associated with heat pump adoption. As such, an interpretive inductive approach was most suited to garner the information required to fulfil the proposed research aims and objectives and ensure the validity of the study [61].

Data for this empirical study were collected via a self-completion structured online questionnaire filled in by Scottish homeowners over the age of eighteen, who had already transitioned to heat pump technologies as their primary domestic heating source. This method was chosen over interviewing participants for numerous reasons. With the main data collection occurring during the summer months, the research had to be conducted in a way that was easy to organise and did not require simultaneous researcher and participant availability. Whilst interviews may have allowed for follow-up questions to delve deeper into certain answers, due to the time constraints and having no prior correspondence with potential participants, the decision was made to conduct the data collection process via an online survey.

Furthermore, collecting data this way allowed for a more extensive research study, both geographically and through the amount of information gathered, as shown in the similar study conducted by Karytsas [34] into the awareness of ground-source heat pump systems in Greece. It also meant that respondents could participate in the survey at their leisure whilst reducing any potential additional researcher bias being introduced to the study, as can happen with a face-to-face interview.

The survey consisted of 22 questions split into four sections. The first section focused on the respondent’s property. Style, age, size, insulation level, and heat demand all impact a property’s heating requirements and usage, so this information was gathered to enable comparisons during the analysis of the results. The second section enquired about their heating systems. Respondents were asked when their heating system was installed, as well as the make, model, and output of their chosen system. Alongside this, participants were asked about the heating system they had transitioned from and whether any other renewable energy systems had already been installed in their property. The information gathered from this section, in conjunction with the property characteristics, could provide a better insight into respondents’ satisfaction levels.

The third section concerned the decision-making process. This information was gathered to help gauge and identify what adopters were seeking when replacing their heating system, the driving factors behind their transition, and the volume of information they had gathered before their adoption of the new system. Within this section, respondents were also queried about their main concerns, and whether they felt fully informed about any limitations associated with their heating system, before the installation. Lastly, participants were asked to pick whether they had gathered feedback from other householders before adoption, and, as a follow-up, to rank how influential that information was on a Likert scale.

The final section required respondents to detail their post-adoption attitudes, aiming to identify what information should be presented to future adopters. This section allowed respondents to comment on any information they wished had been available during their decision-making process. Furthermore, it allowed respondents to provide information on their satisfaction levels with their chosen system, asking specifically whether they would recommend it to others and whether they would still install the technology if they were given the choice again. Finally, participants were asked to discuss any other information that they thought would be helpful to future adopters in their decision to transition their heating system.

Respondent selection was initially conducted using opportunistic sampling, with contact being made with those previously identified as having a heat pump installed in their property. These potential participants were identified using several online resources. Firstly, contact was made with a representative of the GHN, a subsidiary of the Energy Savings Trust. After an initial call to discuss the study, the survey link was distributed to all 148 homeowners registered on the network with a heat pump installed. As the GHN generally consisted of homeowners that were satisfied with their heating systems, as shown by their willingness to use their properties as case studies within the network, finding participants who were potentially dissatisfied meant finding alternative points of contact. As such, online posts were made within several UK-based heat pump groups on Facebook. The users of these groups offered a more varied view of heat pumps, with many posts indicating dissatisfaction with their systems. Finally, posts were made on LinkedIn and Facebook to find participants who may have the technology but may not be a part of these larger specialist groups, who may offer a differing view of these heating systems.

The analysis of survey responses was conducted using the three-step method discussed by Miles, Huberman, and Saldaña [62]. Initially, the questionnaire responses were collated within a database that allowed easy interpretation and comparison of the answers. The data were then reduced by selecting, collating, coding, and categorising them under inquiry to address the key objectives of this study [63]. The open-ended question responses were exported into NVivo (release 13), a qualitative analysis software. It was expected that the data received would illustrate complementary aspects of the central area of research interest: what homeowners want to know about heat pumps prior to purchase.

5. Results and Discussion

By the end of the survey period, complete survey responses had been received by 61 individuals. In total, 78 prospective participants had engaged with the survey; however, 5 were screened out and 12 left the study at various stages before completing the survey. As the sample was purposive (rather than random), the authors felt that the respondent group was able to respond to and explore issues in an informed and experience-led manner, rather than us being required to pose potentially hypothetical questions.

The 61 respondents were geographically located across Scotland, including Orkney and the Shetland Islands, with respondents situated within 25 of the 32 council areas. There was a higher concentration of respondents in the eastern and southern regions. However, this is in keeping with Scotland’s population density figures. Of the 61 respondent properties, 47 (77%) were in rural areas. This sampling is consistent with the study conducted by NESTA [64], wherein 70% of respondents came from rural areas. This suggests that heat pumps are capable of being installed and utilised in even the most rural of locations, such as the Highlands and Islands. The survey respondents resided in properties of various ages. The majority (57%) of the properties (see Figure 1) were built post 1980; 18 properties were built between 1981 and 2010; and 17 were built between 2010 and the present. These figures suggest that many homeowners are adding heat pumps to older properties.

The survey data show that heat pumps have been installed in a range of property types, including detached (twenty-five respondents), semi-detached (seven respondents), and terraced (one respondent) houses. Only one respondent was living in flatted accommodation, residing in a ground-floor flat. Three participants responded “Other”, with one living in a semi-detached cottage, and two living in detached bungalows.

Of those who did know their property’s EPC rating, just under half of respondents (48%) lived in properties with high-efficiency ratings, widely accepted to be the EPC ratings of “A” and “B” [5]. However, although seventeen respondents lived in properties with a “C” rating, two lived in “D”-rated properties, and one lived in an “F”-rated dwelling, due to the high number of “Unknown” responses, any conclusions drawn from this EPC dataset should be interpreted with caution.

5.1. The Chosen Heating Systems

The majority (73%) of respondents to this survey installed an air-source heat pump. This figure is lower than that reported by NESTA [64], yet still represents a significant majority. Fifteen participants chose a ground-source system, and one respondent installed a water-source heat pump. Moreover, 31% of those surveyed (see Figure 2) had previously used mains gas as their primary heating system, whilst 21% of respondents had transitioned from an oil-based system. On the other hand, 18% of participants had had no prior heating system, as their heat pump systems had been installed into new builds.

The final question within this introductory section of the survey prompted respondents to detail any other renewable heating technologies that they had installed within their properties. Most respondents (59%) had had no other renewable heating system installed, while 35% of respondents mentioned the presence of solar panels alongside their heat pump systems. Two respondents had wood-burning stoves and two had biomass boilers. Whilst these findings suggest that some heat pump users are combining multiple renewable energy technologies, indicating a strong commitment to environmental sustainability, the fact that so many have not implies that many consumers approach heat pump adoption as a single-system changeout rather than as a radical whole-package approach.

5.2. Motivations and Influences of Heat Pump Adoption

To determine what information is key to adopters before their transition, the concerns about and influences upon their decision need to be considered. This will enable a well-rounded analysis of the data and allow for more in-depth scrutiny of the post-adoption attitudes towards the chosen heating system.

It is clear, as shown in

Table 1. The importance of factors and respondents’ key motivating factors in the adoption of heat pump technologies.

	Very Important (5)	Somewhat Important (4)	Neither Important Nor Unimportant (3)	Somewhat Unimportant (2)	Very Unimportant (1)	No Response (0)	Mean Response	Key Influencing Factor
Aesthetics of the system	1	14	18	17	9	2	2.7	1
	2%	23%	30%	28%	15%	3%		2%
Carbon savings	42	9	6	1	2	1	4.5	29
	69%	15%	10%	2%	3%	2%		48%
Cost of the system	13	31	9	7	0	1	3.8	2
	21%	51%	15%	12%	0%	2%		3%
Disruption during installation	2	10	16	16	16	1	2.4	0
	3%	16%	26%	26%	26%	2%		0%
Fuel bill savings	17	26	8	7	1	2	3.9	12
	28%	43%	13%	12%	2%	3%		20%
Government policy	6	12	18	7	17	1	2.7	0
	10%	20%	30%	12%	28%	2%		0%
Incentives offered	21	22	7	5	6	0	3.8	3
	34%	36%	12%	8%	10%	0%		5%
Noise from the system	8	21	11	12	8	1	3.2	0
	13%	34%	18%	20%	13%	2%		0%
Reputable installation company	32	18	5	2	3	1	4.2	1
	53%	30%	8%	3%	5%	2%		2%
Size of the system	17	20	15	5	3	1	3.7	0
	28%	33%	25%	8%	5%	2%		0%
Thermal comfort	40	18	2	0	1	0	4.6	11
	66%	30%	3%	0%	2%	0%		18%

as a calculated mean response, that those surveyed appear most concerned with factors related to environmental impact (carbon savings), thermal comfort, and the reputation of the installation company prior to heat pump adoption (shading indicates the most popular responses). These findings are largely in keeping with the categories of barriers to adoption posited by BEAMA [18].

Financial factors relating to the adoption such as fuel bill savings and the upfront costs, along with the available incentives, were also of high importance to many respondents. Whilst fuel bill savings were deemed a key motivating factor by 20% of participants, relatively few indicated that incentives were significant to their transition. One might suggest that there is a complex relationship between incentives to support installation and financial benefits throughout the life cycle of the system. These findings—for this respondent group—also contradict the hypothesis by Jacksohn et al. [44] that reasonable incentives could steer households towards microgeneration technologies. For the respondent group in this study (i.e., early adopters in Scotland), incentives were identified as the key motivation by only three respondents, although the fact that 48% cited carbon savings as their key driver may suggest that this group is motivated by wider environmental issues. Likewise, 83% of respondents deemed a reputable installation company to be important. However, only one respondent indicated that this was a key influencing factor in their adoption.

No factors were deemed overwhelmingly unimportant, although respondents appear to place less importance on the aesthetics of the system; any disruption that may be caused during installation; and government policy. The findings suggest that adopters consider multiple aspects surrounding the technology and adoption process as equally important. These findings support the conclusion reported by Michelsen and Madlener [60] that heat pump adopters were multilaterally motivated, rather than purely convenience- or consequence-orientated.

5.3. Pre-Adoption Concerns and Considerations

Alongside establishing the motivating factors that lead to heat pump adoption, our survey invited respondents to detail their main concerns prior to adoption. The concerns uncovered were split into four distinct categories: suitability, financial, environmental, and knowledge concerns. Similar to the motivating factors, these categories are also in line with the barriers to heat pump adoption put forward by BEAMA [18].

Interestingly, it appears that a small proportion of participants (10%) had no significant concerns or reservations prior to adopting heat pumps. This suggests that, for some individuals, the decision to adopt a heat pump is relatively straightforward. Interestingly, no respondents mentioned concerns about disruption during the installation process, in contrast to the findings of Caird and Roy [38] and their UK-based study into barriers to adoption.

5.3.1. Suitability Concerns

There were 32 references to suitability factors within the survey responses. These responses were further divided into three subcategories: machine suitability (twenty-four references), property suitability (two references), and installer suitability (one reference).

With regard to technical suitability, the most common concern (11 references) related to the thermal dependability of the pump and “whether it would be sufficient to heat the house in winter” (Respondent 44). General system reliability and efficiency was another concern voiced by several respondents. Respondent 47 was concerned with the long-term viability of the installation. Noise was noted as a concern by only two respondents, indicating that the documented potential for noise from units [65,66] appears to not have a significant impact on adoption rates, at least in the minds of early adopters.

It is apparent from the responses that very few adopters were worried about how the system would work within their current property. Only Respondent 9 was concerned about how the system would be “retrofitted into a modern house”. This suggests that many adopters trust that the system can be integrated into their current property as is. These results are possibly due to respondents feeling that their properties are already suitably adapted for optimal heat pump usage. Only one respondent lived in a property without modern insulation, residing in a solid-walled property. Of the remainder, 49 respondents (80%) lived in “fully insulated” properties; 3 respondents had retrofitted external wall insulation; three had cavity wall insulation; and 5 stated that they had some loft insulation.

5.3.2. Environmental Concerns

Unexpectedly, there were relatively few concerns regarding any potentially negative environmental aspects of the transition (such as embodied carbon). Whilst it would be expected that few responses would query the environmental benefit of the system, only three respondents focused on environmental factors that concerned them before the adoption. For Respondent 37, their concerns were surrounding the “climate crisis”, whereas Respondent 33 wanted to install “a good sustainable system”. Although these findings corroborate the research conducted by Jacksohn et al. [44], who found that environmental concerns were of less relevance to adopters, they are striking considering the fact that carbon savings were the key motivating factor for so many respondents (48%). Perhaps participants were concentrating purely on the physical technology or installation rather than the macroeconomic factors surrounding the adoption.

Interestingly, Respondent 26 remarked that “it’s essential we turn to electricity to heat our homes rather than fossil fuels”. It is worth noting that, while electricity can be generated from renewable sources like wind and solar, historically, the majority (across the UK) has been generated from fossil fuels. In Scotland, however, the generation of electricity through hydro schemes has been established for many decades, and significant advances have been made in decarbonising the electricity generation across renewable, non-renewable, and nuclear energy sources.

5.3.3. Financial Concerns

Once more, it is surprising that few respondents had economic concerns. There were only two references to the upfront cost of the system and only four concerns voiced regarding the ongoing costs relating to the system. Therefore, it could be reasonably hypothesised that economic factors, if they are indeed a key motivator, are effectively communicated to potential adopters before the transition, addressing any cost-related concerns.

5.3.4. Knowledge Concerns

Six individuals noted concerns regarding the knowledge of the installer. This category, more than others, highlighted how each installation and experience is unique. Respondent 8 wanted a “reputable and knowledgeable installer…a single point of contact and a turn-key system”, Respondent 16 needed an installer who could implement a specialised hybrid system, and Respondent 40 had concerns about a ground system being installed in their mature garden. A few respondents appear distrustful of various heat pump stakeholders, with negative comments being made regarding salespeople and advice services, in keeping with the results of the 2023 BEIS study. Respondent 14 worried about “false claims by the salesmen and brochures”, and Respondent 46 remarked on the “stupidity of Home Energy Scotland”. Although experiences and feelings of a minority group, these findings indicate that prior consumer bias towards specific groups, e.g., salespeople, can influence an individual’s decision to transition their heating system.

5.4. Systemic, Property-Related, Financial, and User-Related Limitations

The next set of questions aimed to identify how much information householders had gathered before their transition. Participants were queried about any limiting factors that were discussed before installation. The responses were coded into four categories: systemic, property-related, financial, and user-related limitations.

Overall, 49 of the 61 (80%) respondents felt fully informed about the potential limitations. One participant stated that they felt fully informed despite no limitations being discussed with them. A total of 27 responses mentioned system-based limitations, with 12 references to thermal aspects. Seven of these responses expressed that limitations regarding the use of the system in cold and winter weather were discussed. In addition to this, there were six references to the lower running temperature of the system. Those responses categorised as regarding efficiency and reliability limitations were also primarily thermal-related; however, they focused on slower response times and the heating speed of their system compared to gas-fired boilers. Alongside this, installers discussed whether the system could reliably work in winter. Three respondents said they were notified about potential noise from the system. One response of particular interest from Respondent 47 commented on the “limited life of ground source”, a factor not mentioned by previous research or other ground-source system users.

With regard to the property-based limitations discussed, 20 respondents referred to potential compatibility issues with their property and current heating system components like radiators. Four respondents were told that their radiators would need upgrading, with Respondent 60 noting that there would be a need for larger radiators on upper floors compared to if the system were powered by a typical gas boiler. Three respondents were informed that a larger hot water cylinder would be needed, or else the system would need supplementing with an immersion heater. Three respondents discussed insulation levels and whether they were sufficient for the heat pump to work well. Interestingly, two of those three respondents lived in properties they considered to be fully insulated, with the other living in a property with only loft insulation.

Other responses included individual situations. Respondent 20 discussed potential issues with their gravity plumbing system, and Respondent 13 queried the capacity needed for a four-bedroomed house when there are only two occupants. These findings highlight how unique each installation is. A comparison of these findings with the earlier study by the Energy and Climate Change Directorate [3] indicates that there is a potential need for information tailored to individual properties and situations to aid the diffusion of heat pumps rather than widespread campaigns.

Again, the financial aspects discussed were divided into upfront costs and ongoing costs. There was only one reference to upfront costs, with Respondent 54 disclosing that grants were discussed before adoption. However, no further information was provided about what potential limitations around grants there are. Four respondents were told about increased running costs, with Respondent 3 explaining that they were told the “cost of heating would not decrease as swapping from gas to all-electric heating was more expensive”.

It is somewhat surprising that only two respondents discussed potential user-related limitations prior to heat pump adoption. Respondent 26 was advised that they would “need to slightly alter the way” they used their heating system, and Respondent 61 had it explained that “a heat pump works in a different way to a gas boiler”. If these statements hold, it would be presumed that more installers would be informing potential adopters about these limitations. Of course, one could argue that any shift in the choice, use, and operation of technology requires some degree of adjustment, and this is certainly not unique to heating systems.

Perhaps the most intriguing discovery in this section is that, even though most of the previously mentioned concerns were addressed with potential adopters, only three individuals believed that they had covered every aspect before installation. This observation suggests that there may still be a gap in the supply of comprehensive and cohesive information to potential adopters by installers, perhaps leaving adopters to rely on their independent research to address their concerns.

5.5. The Influence of Peers

It was hypothesised that information sourced from peers could increase the likelihood of heat pump adoption and enable widespread adoption. As such, participants were asked whether they had gathered any information or feedback from householders who had already transitioned to a heat pump. The split between those who had gathered information from other householders (31 respondents) and those who had not (30 respondents) was almost equal.

A large majority (87%) of those who responded “yes” indicated that this information was influential in their decision-making. Only four respondents (7%) felt that this information was moderately or very insignificant to their decision-making process. These findings broadly support the work of Franceschini et al. [31] and other studies in this area linking peer recommendations and microgeneration adoption. Alongside this, Respondent 15 disclosed that they had “recommended [their system] to two neighbours who now use air source”, highlighting how behaviourally informed “nudging” through shared consumer testimonials [29] can influence others and increase the likelihood of adoption.

5.6. User Satisfaction

The subsequent survey section explored post-adoption attitudes, including satisfaction levels, whether respondents would recommend their system to others, and willingness to install the same system again. This aimed to uncover any ongoing concerns or previously overlooked limitations, which could inform future awareness campaigns for prospective adopters.

Most respondents (80%) were “very satisfied” with their heat pump systems. Ten respondents felt “slightly satisfied” with their chosen heating system. This overwhelming majority of satisfied users supports the findings of previous studies [42,64].

Further comparing user satisfaction with respondents’ pre-installation information levels (Figure 3) suggests that feeling informed pre-adoption influences satisfaction levels post adoption. Of those who felt “very satisfied”, 88% of respondents felt “fully informed”. There was an equal ratio of informed and uninformed respondents who expressed feeling “slightly satisfied” with their system. Respondent 23, who marked “slightly dissatisfied”, also conveyed that they had not been fully informed of the limitations, explaining that this sentiment was due to the system being “not warm enough and quite noisy”.

Moving now onto whether the respondents would endorse their heating system to others, 57 (93%) expressed their willingness to do so, whilst only 4 indicated that they would not. Those four respondents noted various reasons for why they would not recommend the system. Again, noise was a factor, with both Respondents 2 and 23 stating that the system was louder than expected. There was one reference to the system not being warm enough. Respondent 28 stated that they would “only recommend [the heat pump] if you could find a…cheaper way of running” the system, and revealed that they installed solar PV panels to combat the added expense of the heat pump. Interestingly, and rather pragmatically, Respondent 6 said that they would not recommend their system as they “don’t know enough about people’s circumstances to make a recommendation”, again highlighting how important individually tailored information may be to the widespread diffusion of these technologies. Overall, 98% of respondents would choose to install their current heating system again—a remarkable figure that suggests heat pumps are meeting or even exceeding the expectations of most homeowners. Of course, it should also be recognised that the respondent sample comprised “early adopters”, where there may be complex relationships between motivation, expectations, and satisfaction.

5.7. Recommendations and Insights for Future Adopters

Finally, respondents were asked whether they wished any additional information had been available during their adoption process or whether they could offer any additional advice that they felt could aid other householders to make a better-informed decision when considering transitioning.

Responses to this question covered a wide range of topics, with conducting extensive research before adoption being a popular recommendation. Two respondents recommended finding and working together with certified installers. Respondent 46 advised “always keep[ing] correspondence to quote back to stupid authority”, suggesting that they had a potentially challenging experience. Respondent 52 advised using the “Heat Geek” website as an independent source of advice. Three respondents mentioned the GHN and how they should be used “to get unbiased advice from existing users”. Their fellow advice service, HES, faired less positively. While two respondents praised their helpfulness, two others had differing views, mentioning “not even HES could guide us” and how they would have liked “more clarity and less stupidity from HES”. Respondent 20 urged those considering adoption to not “accept answers from ‘experts’ without doing your own research”, a feeling echoed by Respondent 3, who noted the “lack of understanding in utility companies of ASHP”. Six respondents advocated for the utilisation of peer recommendations, with Respondent 15 advising potential adoptees to “go and talk to households that have one and ignore those who haven’t”. These responses support the evidence from previous studies regarding trustworthy sources of information (e.g., [21,24]).

Five respondents mentioned aspects of their property’s characteristics alongside their positive installation experience. Respondent 7 noted how their experience shows that heat pumps “can be successfully installed in older houses”, and Respondent 40 recommended that “all households should have one”. Respondent 37 emphasised the “importance of ‘tuning’ the installed ASHP system to your particular property and requirements”, a sentiment shared by many. Moreover, 12 respondents highlighted the importance of insulation: one of the most common caveats attached to the participants’ recommendations. Respondent 57 urged those considering adoption to “invest as much as you can on insulation”. Furthermore, Respondent 12 noted that they “would not recommend it for an average UK house”, and Respondent 35 agreed that there was “no point installing a heat pump in a poorly insulated home”. These numerous recommendations echo those of the study by Holland et al. [26], who advocated improving insulation levels in pre-1914 properties before adoption.

Multiple references were made to complementary technologies enhancing heat pump efficiency and user satisfaction. Two respondents recommended using under-floor heating rather than radiators to combat any thermal limitations. Additionally, six respondents recommended the use of solar PV panels, with Respondent 36 claiming that they “anticipate a net zero cost for household energy for a least 4 months every year”. With carbon savings and financial factors identified as key motivating factors, utilising information like this could provide real, informed, and understandable figures to potential adopters.

Four respondents expressed a desire for better information regarding the expected disruption during installation, particularly those with ground-source systems. For instance, Respondent 17 highlighted that their installation caused significant groundwork damage. Alongside this, noise was a recurring topic, though interestingly two in three respondents found the units to be quieter than anticipated. However, Respondent 56 cautioned against placing the unit near a bedroom due to morning disturbances.

Lastly, several respondents highlighted a need for additional post-adoption support from installers. Respondent 22 explained that “there is important learning to be made regarding using the controls to minimise consumption while improving comfort”. Two respondents felt they were lacking information that could aid their use of the systems, with Respondent 59 noting that they “would have liked to have known that the internal pump putting water round the radiators stays on nearly 100% of the time, even when the radiators feel completely cold”. As noted by Respondent 24, it appears that a frustrating aspect of the adoption process for many is “the kind of fit and forget approach of our installers”. Consistent with the study by Corbett et al. [29], these results underscore the ongoing necessity for additional support and guidance on system usage, including maximising efficiency and realising the heat pump’s full potential.

6. Conclusions

The existing research indicates a need for more tailored awareness campaigns regarding heat pumps to surmount the perceived barriers, whilst improving the appeal and adoption rates of heat pumps within Scotland. This research study therefore concentrated on understanding why domestic heat pump adoption figures have remained low. The novelty of this research lies in the combined emphasis on “actual” early adopters (building on a GIS-based study undertaken by Min et al. [67]) and adopters across a range of properties in Scotland. The consideration of how to deal with older properties complements studies by the likes of Lamb and Elmes [68], who identified significant differences in the readiness of older and more recent properties to incorporate and benefit from heat pumps. One could argue, of course, that the question of “non-adoption” is both complex and difficult to answer, given the potentially vast respondent group. However, by taking the approach described here, we have been able to explore how connections between experience, communication, and guidance appear to remain at the heart of how the country can address the need for greater levels of installation and use.

Our online survey collated a valuable amount of information regarding the pre- and post-adoption motivations, concerns, and attitudes of current domestic heat pump users in Scotland in order to provide a deeper insight into how future heat pump campaigns can be focused. The findings of this study indicate that heat pump technology is capable of widespread adoption, having been utilised in properties of different types and ages, as well as in a range of Scottish locations. Of course, one should recognise that the survey sample was composed of early adopters, whose motivations may well differ from those of users in the coming years.

This research uncovered several factors that need to be addressed to aid the dispersal of heat pumps. The most important is the identified need for improved ongoing support for current users. If peer recommendations have a sizeable influence on the rate of diffusion of technologies, as indicated by this study, then it is clear that the primary focus should be on providing the necessary help and support to current users to ensure they are fully comfortable with their heating systems. This study also found that heat pump adopters are generally prompted by multiple motivations, rather than one singular key factor. Alongside this, this study has found that each installation is unique to not just the property but also the individual user requirements. As such, these findings have significant implications for the understanding of why the adoption of heat pumps within Scotland has fallen short of expectations. Just like the installation process, it appears that there is no “one size fits all” approach to the dissemination of these technologies that can be used.

Connected to this is the issue of the life-cycle costs of heat pump installation and operation. Whilst the survey results signalled the importance of fuel bill reduction to adopters, there was less concern regarding the costs, incentives, and carbon implications of the installation phase. Whilst, on the one hand, it is heartening to witness a growing awareness of the importance of energy performance, a disconnection from the initial (and end-of-life) stages is problematic. Further exploration of attitudes, awareness, and perception of the life cycle would usefully inform future initiatives. This paper serves to identify this as a key factor, in that the actual running costs (and how these are associated with issues of comfort and meeting client expectations) should be explored by further studies.

Considering our research findings, it has become evident that the specific topical focus for future awareness campaigns may hold less significance than previously assumed. This study reveals that potential adopters seek to feel informed and prepared before adopting a heat pump. Therefore, the emphasis should be on providing potential adopters with easily accessible, comprehensive, and reliable information on a range of topics. Nevertheless, we also recognise that this study dealt with a deliberately narrow respondent group, and that a wider study—also involving non-adopters or individuals who actively reject the technology—is required to fully address the subject area. It would also be useful to replicate aspects of this study in other regions, to determine where there may be obstacles to the transfer of knowledge across wider geographical and political contexts.

Overall, though, whilst there are concerns for many heat pump users before adoption, addressing limitations before installation increases the likelihood of user satisfaction. As shown by this study, satisfied users are more likely to recommend the system to others, thus facilitating the effective and efficient widespread adoption of heat pumps in Scotland.