To maintain the global temperature rise at or below the targeted 2 °C (from the pre-industrialized temperature level), urgent and fundamental actions must be taken [1
]. The European Union (EU) is committed to reducing its greenhouse gas (GHG) emissions by 80–95% from the 1990 level by 2050 [2
], and the buildings sector is a priority area for meeting the target [3
]. Globally, residential buildings account for 24% of total final energy use, which equates to 14% of global GHG emissions [4
]. Thus, reducing the use of energy in the housing sector plays an important role in mitigating climate change. The new building stock boasts better energy efficiency than the older (but current) stock; however, as the building renewal rate is slow, it is important to improve energy efficiency and to increase the use of renewable energy in current buildings. Of all buildings in the EU, 74% of the floor area comprises residential buildings, and in turn, 66% of that area comprises detached houses [5
]. Also, in Finland, new detached houses are not built as actively as before [6
], which increases the value of improving the state of current houses. Therefore, owners of detached houses constitute a significant group to be taken into consideration when one thinks of ways to reduce GHG emissions. This group could reduce their contribution to GHG emissions by changing their heating systems, by implementing renewable energy production technology, and by adjusting their daily habits of energy usage.
Thus far, existing research has mainly focused on technologies related to energy efficiency and renewable energy. The role of consumers—who actually make the decisions—has not been researched as much. Based on a survey of 1250 residents, Newton and Meyer [7
] established three types of environmental lifestyle segments: ‘committed’ greens, ‘material’ greens, and ‘enviro-sceptics’. Only a few differences were found in the actual consumption of energy, housing space, etc. among the segments. The research suggests that certain factors, related, for instance, to information, finance, and organization, override attitudes, opinions, and intentions as indicators of consumer behaviour. Ek and Soderholm [8
] sent out a postal survey to 1200 Swedish households to analyse their willingness to save electricity by changing daily habits. The results indicated that important factors of energy-saving activities are cost, environmental attitude, and social interaction. They found no statistically significant impact from socio-economic background factors.
Valkila and Saari [9
] used consumer panels to gather data about consumer attitudes and potential for readiness to act in a more environmentally friendly manner. The themes of the study were urban structure, household energy consumption, mobility, and lifestyle. Based on the results, all research subjects were willing to reduce their consumption, but they were not ready to invest in more expensive, environmentally-friendly equipment.
] identified factors affecting the building envelope renovation decisions of detached-house owners. Based on the three approaches used, it was concluded that renovation decisions are affected by technical parameters and by general housing activities more than by socio-economic factors. The most oft-cited reasons for insulation were the building lifespan and environmental and energy considerations. Economic savings and fiscal incentives were mentioned only rarely. Also, Banfi et al. [11
] evaluated consumers’ willingness to pay for the insulation of windows and facades and for ventilation systems. Their results demonstrated that consumers value energy savings, environmental benefits, and comfort benefits. However, in addition to legal, structural, and socio-economic hurdles, consumers felt that information is lacking concerning the benefits of energy efficiency measures, and that possibly the methods are insufficient for evaluating the benefits in economic terms.
Even though the role of consumers has been researched [12
], the focus has been mainly directed at general attitudes and electricity saving [13
]. What has not been researched as much is knowledge of and attitudes toward different technologies for using renewable energy, and the barriers encountered by consumers. Therefore, the research questions which this paper poses are as follows:
The findings from our research are similar to those of Newton and Meyer [7
], as they suggest that factors related to information and finance override other factors, such as attitudes, as indicators of consumer behaviour. Our results are also similar to those of Ek and Soderholm [8
], as their findings indicate that important factors of energy saving include those of cost and environmental attitude. Valkila and Saari’s [9
] research subjects were willing to reduce their consumption, but were not ready to invest in more expensive equipment. However, based on our findings, people are willing to invest in technologies when they have a sufficient level of information and amount of money. In Jakob’s [10
] research, the reasons listed for adding insulation rarely pertained to savings and fiscal incentives, which is the opposite of our research findings.
As Figure 4
shows, most respondents perceived that economic factors have the most impact on implementing new technologies. Interest in cheaper technologies, such as air source heat pumps, may indicate the same. Also, the majority (88%) of respondents were interested in saving energy to achieve economic savings, although almost half (47%) thought they would not be able to save enough energy to obtain considerable economic savings. We did not ask in the survey what the respondents considered to be considerable savings; thus, there might be variation in the replies. This aspect could be a topic of further studies. A third of respondents replied that receiving financing would assist them in making improvements with energy production technologies. In Finland, until 2017, it was possible to get discretionary grants for materials for energy renovations of detached houses, but these grants are no longer available, as Law (22.12.2005/1184), which the grants were based on, was repealed [24
]. Even though the expenses of the work performed may still partially be deducted from taxes as household expenses [25
], there might be a need for new kinds of funding instruments, such as energy loans with low interest rates offered by the government.
Based on our findings, we conclude that the respondents desire more information on the resulting costs and possible savings of renewable energy technologies. As we did not specifically ask what kind of information the respondents would like and in what form, the matter could be researched further. There are already multiple free calculators available providing detailed information about annual savings and costs, using different repayment periods.
Based on our survey results, 42% of respondents named a better understanding of technologies
as an important factor in the decision to implement new technologies. The same need for information is also manifested in Figure 2
, which indicates some technologies were unfamiliar to over a third of respondents. The survey did not specify what sort of information the respondents were lacking; therefore, that too could be researched further. However, it should be noted that merely knowing more about the technologies does not necessarily increase the implementation rate, as respondents with educational background in technology had not implemented the solutions more than the other respondents had.
Based on the LCA model, implementing air source heat pumps has the biggest influence on reducing the residential areas’ GHG emissions. This is because the respondents had most considered implementing air source heat pumps (although half of the respondents had already implemented them). Ground source heat pumps and air to water heat pumps would have a greater effect on the GHG emission reductions, but since the investment costs are higher and they are more difficult to install, they appear to be not as popular. Also, if a house has direct electric heating, it most likely does have the necessary water-circulating heating system, and ground source heat pumps cannot be installed on every lot. Energy efficiency of housing could also be improved by installing new monitoring technologies which would lead to the reduction of GHG emissions.
We cannot be sure that respondents answered the survey questions truthfully, but we have no reason to believe they would have sent false replies. Also, the same problem is faced with all survey-based studies. Houses in the area researched are on average newer than in Finland in general [26
], and the number of houses heated by electricity is approximately double that of Finland’s average [27
]. These issues may somewhat influence the generalizability of the research. Also, in the calculation of GHG emissions, we assumed that the energy classes of the houses would not change despite the improvements made; thus, the yearly energy consumption would remain the same. The energy production systems that respondents had considered the least were not included in the LCA model. If these factors had been considered, the possible GHG emission reductions could have been greater than those calculated. However, some respondents had considered more than one energy production system, and in reality, they would most likely implement only one, which was not taken into account when we made the calculation. The calculation was based on the respondents’ interests and current knowledge, which are not necessarily the most rational. Therefore, it is possible that with the same energy-efficiency investments, the GHG reductions and economic savings achieved could be greater.
The research was carried out in a small area, so the impact pertaining to reducing GHGs from that area would be insignificant even on a regional level. However, the results can be generalized to a wider area, as detached houses account for 27% of the energy consumption of Finland’s total building stock [21
]. A quarter of the housing building stock was built in the 1960s and 1970s, and buildings from those decades are currently mostly renovated [28
]. Thus, consumers play an important role in reducing GHG emissions, and in turn, in mitigating climate change. The results can also be generalized to other countries and areas with somewhat similar climate and buildings. In a warmer climate, the achieved reductions would be smaller, as the percentage of energy used for space heating is not as great.
Based on the survey and the LCA model created, the reduction in GHG emissions would be 15% in the areas studied. This is still far from the EU’s reduction targets and carbon neutrality, and it indicates that consumers cannot be overburdened with too much responsibility. In the areas under study, the greatest GHG emissions originate from the production of electricity. Thus, the biggest reductions could be achieved by increasing the share of renewable energy in the production of electricity.
It worked well to combine the survey with LCA modelling. The survey yielded data from consumers for use in the LCA model, and the model provided numeric data supporting the survey.
A survey was distributed to owners of detached houses in order to obtain information about their attitudes towards renewable energy solutions and their willingness to implement them. Also, barriers to the implementation of these solutions were examined. A lack of knowledge of annual economic savings, of resulting expenses, and of different technologies were the three most cited barriers. Based on the results, the solutions that respondents were most interested in were air source and ground source heat pumps, solar electricity, and solar heat.
An LCA model was created to be able to estimate how much reduction in the households’ GHG emissions could be achieved if the respondents were to implement the solutions they had considered. The results indicated that the reduction could be 15% of the annual emissions. The reduction is not the most optimized, and a greater reduction could possibly be achieved in the areas if the respondents had had better knowledge of economic and technological issues. The use of a survey to acquire data for an LCA model worked well. Future research could focus on the kind and form of information consumers need to implement more technical solutions based on renewable energy, and on what people consider to be real economic savings achieved from saving energy. Finally, it would be a point of interest to observe how the results would differ if the survey was conducted in another country.