## 5 Conclusions  
In Spain despite the generalization of EPCs in 2013, in transposition of the EPBD (2010/31/UE), there is no clear evidence on the diffusion of efficient homes nor retrofit of existing ones. Existing research reviewed in Section 2.3 in this paper offers inconclusive evidence on the effectiveness of such an EU policy. Drawing on statistical analysis of prices, small, uneven and even non-existent correlations among home prices and EPC ratings have been found. Viewing surveys and interviews given to real estate agents and property experts a number of issues arising from the EPC scheme have been pointed out. As a consequence, such a scheme is seen as ineffective in fostering end users to engage with efficient premises. In turn, designers, builders, developers and other agents in the housing industry do not place a special interest in delivering homes with an energy benchmark surpassing the minimum required by construction codes. Not surprisingly, EP certified \"A\" or \"B\" buildings only account for 1.1% of all EPCs. Whether such lack of interest on efficient premises comes from a lack of perceived co-benefits requires further exploration. This paper sheds lights on such understanding by surveying a large sample of households that have recently participated as buyers, sellers, tenants and landlords in the Spanish housing market. Namely, the interest of the research is placed in: (1) learning whether such agents do perceive selected co-benefits of efficient homes in the form of energy savings and comfort; (2) whether such perception is influenced by respondents' current living conditions; and (3) whether it is influenced by their sociodemographic features including the housing tenure and the role they have played within the real estate market. Figure 7: Regression model to identify the factors influencing the perception of EE benefits. Source: Self elaboration. Results suggest that the assessed energy performance co-benefits seem to be well established among respondents. Interestingly, such perception is stronger in the case of thermal comfort than energy savings. This finding is quite relevant since in Spain the prescription of efficient premises has been only based on signaling the potential energy savings and CO2 emissions, putting aside any other co-benefit. In turn there is room for energy policy improvement by signaling comfort and other benefits identified by past research. The second finding is that efficient homes are not perceived as deserving a larger market value. Such a conclusion is in line with historic research in the country that has found, as previously stated, a small or even null correlation between EPC ratings and prices. When the perception of the assessed co-benefits is analyzed in detail to learn differences among respondents, relevant specificities emerge. It seems that elder, wealthier, homeowner and male respondents perceive to a greater extent the energy performance co-benefits. Interestingly, the relation seems to be far from linear: There is a larger gap between low-income and medium-income households in relation to medium and high-income ones, which suggest that educational attainment may play a role in understanding the relationship between efficiency, energy savings and comfort. Interestingly, landlords, irrespectively of if they play a role as buyers, sellers oressors, do place a large relevance to co-benefits. This finding also challenges public policy in a country where 72% of homes are owner-occupied at the time that housing policies foster tenancy as an affordable housing tenure. The perception of co-benefits, beyond personal attitudes, should be influenced by respondents' close built environment in the form of living conditions as hypothesized in this paper. Such living conditions can be assessed by learning about the household's current home retrofit requirements and priorities to carry out such retrofits.