## 1 Introduction
### Barriers to Energy Performance Diffusion  
Despite the worldwide knowledge about the importance of reducing CO2 emissions and energy consumption in order to stop climate change, the adoption of energy efficiency criteria in buildings still finds multiple barriers. The EU Energy and Climate Commissioner in 2017, [PERSON], identified some of them as explained below [10]. Regarding the origins of the barriers it is possible to distinguish between:  
* Economic barriers; as the lack of economic or tax incentives (which in Spain is worsened by the dispersal of local, regional and state regulations and jurisdictions), the incremental cost of the design and construction of a new building when it includes a comprehensive study on energy performance, the uncertainty of energy savings and the long payback periods.
* However, the barriers go beyond economic aspects since there are socio-cultural barriers embedded, such as the lack of public awareness or the change resistance of the construction industry.
* There are also technical barriers regarding the inadequate technical training; the projects dispersion and diversity or the scarce data about the projects' performance, not to mention the green-wash that is still used by many companies when mentioning just one building energy performance improvement, hiding or neglecting the relevance of other issues [11].  
However, a large proportion of the causes for the slow dissemination of energy efficiency measures applied to the construction sector lies with individuals themselves. This conclusion was put forward by the study of [PERSON], [PERSON] y [PERSON] [12]. Such authors used a survey applied to 23 stakeholders in order to learn their motivations to implement sustainable criteria in property design and development. Their interviewees came from public and private building organizations including civil servants, developers, design firms and architecture schools. The results of such a study were interesting given that 70% of respondents recognized the need to have implemented sustainability criteria due to regulatory requirements, not because they have any personal interest resulting from belief on an objective. Only 17.6% said their actions were motivated because they perceived that final clients were interested in the benefits of energy performance. Such conclusions are compatible with the goal of the EPBD, as said before, to provide information symmetry regarding private (e.g., energy savings) and public benefits (e.g., environment conservation) of buildings' energy performance.  
When referring to the benefits perception it is necessary to distinguish between energy consumption and energy demand, as explained by [PERSON] et al. [13], \"If energy savings and efficiency were just measured in terms of consumption, it might appear the paradox of talking about large savings when actually no previous consumption to be reduced did exist\" (authors self-translation), which usually happens to people living under fuel poverty conditions. This suggests that when developing energy efficiency criteria in residential buildings passive solutions should be prioritized. It must be stressed this way to technicians and suppliers, against industry preferences based on consumption reductions through facilities renewal, a strategy that has the opposite effect, as was seminally argued by [PERSON] in his book \"The Coal Question\" [14], demonstrating that when efficiency grows, immediate consumption decreases, but the use of the new efficient technology increases, which ends with a higher global consumption.  
As a matter of fact, these barriers are nothing else but opportunities, among them: Specific technical training, new products and materials, jobs creation and new economic incentives, all of which must be well-directed according to the socio-economic field and living conditions of the residential target. However, the adoption of these new technologies largely relies on the perception of potential benefits as next discussed.