## 2 Background
At the other end of the scale, receiving an F or G rating reduces the price by 10.6% relative to \"D\"-rated properties, ceteris paribus. Finally, in the study, the same functional relationships with reference to rental prices have been investigated: with reference to D-rated properties, \"A\" properties experience rental rates that are 1.8% higher, and, counter-intuitively, the premium is even higher for B-rated properties at 3.9%. Furthermore, a decrease of 1.9% for label E and 3.2% for labels F and G has been detected. A positive variation in selling prices in correspondence of the higher labels and a negative differential for the lower labels have been found in the United Kingdom in the study carried out by [PERSON] et al. [59]. By collecting a study sample consisting of 300,000 residential units, the implementation of a hedonic model has allowed one to determine (i) positive changes equal to 5% for residential units characterized by the highest energy labels \"A\" and \"B\" and to 1.8% for housed with intermediate energy label \"C\" and (ii) negative variations on average equal to \(-0.8\%\) for housing property with the lowest energy labels (\(-0.7\%\) for energy label \"E\" and \(-0.9\%\) for label \"F\"). In a study on the Swiss real estate market by [PERSON] et al. [60], a greater willingness to buy energy-efficient properties has been observed, by attesting a market appreciation up to 13%. The research carried out by [PERSON] et al. [61] has aimed at investigating the market appreciation energy efficiency, analyzing its impact on residential property prices in Portugal. Through a set of approximately 256,000 residential properties sold from 2009 to 2013, the results have attested to a premium equal to 13% for the most energy-efficient apartments (i.e., those of EPC labels \"A\" or \"B\") and a market price premium between 5 and 6% for single-independent houses. In Italy, several studies on the effects of energy efficiency on property values have been carried out. [PERSON] and [PERSON] [62] have assessed the impacts of energy redevelopment interventions on the market prices by determining a positive unit variation equal to 26.44 euros per m\({}^{2}\) for each energy label considered. Moreover, by using an evolutionary polynomial regression model, [PERSON] et al. [63] have revealed an increase of 27.94% for class \"A\" and a discount of \(-\)26.44% for class \"G\". Through the implementation of a hedonic model, the Australian Bureau of Statistics [64] has analyzed the functional relationships between the Australian Capital Territory selling prices detected in the two-year period 2005-2006 and the properties energy labels. In particular, the analysis has allowed one to identify an increase correlation for each energy rating label that in Australia is defined as a score between 0 and 6: an increase equal to 1.6% for rating category 1, to 3% for score 2, to 5.9% for label 3, to 6.1% for category 4, and 6.3% for rating categories 5 and 6 have been detected. By comparing selling prices between energy certified and non-certified properties, [PERSON] et al. [24] have calculated an increase equal to $85 per m\({}^{2}\) for properties characterized by an energy attestation, in order to demonstrate the relevance of energy aspects on real estate market. By recalling the same goal, [PERSON] and [PERSON] in 2012 [65] have found that residential units with energy certification are more appreciated than non-certified buildings (+9%). In the Singapore real estate market, [PERSON] and [PERSON] [66] have analyzed the relationship between Green Mark Certification (GMC) and the selling prices by recording an increase equal to 9.61% for Gold Plus, to 9.64% for Gold, to 12.97% for Certified, and to 27.74% for Platinum, compared to houses without GMC. With reference to the current incentive of interventions aimed at energy retrofit of existing housing stock, the present research intends to analyze the economic effects of these operations on the market value of Italian property assets.