## 3 Methodology  
With reference to the aims of the present research, the methodology proposed intends to provide an operational approach for the assessment of economic benefits generated by energy improvement interventions on existing residential buildings. It is articulated into six phases that are described below and are implemented with reference to the selected case study:  
Phase 1--Analysis of the reference context  
* Definition of the most frequent/common building typology;
* Identification of the average property internal area;
* Definition of the property constructive and functional factors.  
Phase 2--Description and localization of the study samples  
* Determination of the urban areas (central, semi-central, and peripheral).  
Phase 3--Analysis of the unit energy retrofit costs  
Phase 4--Data collection of selling prices of properties with high energy label (\"A\", \"B\", and \"C\") and low energy label (\"E\", \"F\", and \"G\")  
Phase 5--Assessment of economic benefits  
* Determination of the value differential between the post-energy intervention situation and ante-energy intervention situation;
* Evaluation of the break-even incentive.  
Phase 6--Development of geographical maps of economic benefits  
* Convenience maps;
* Isoprofit maps.  
In Figure 1, a summary of the main steps for the implementation of the methodology proposed is reported.  
The proposed methodology constitutes a logical procedure to be performed for the assessment of the economic benefits deriving from energy retrofit interventions. It considers the main variables that play a central role in the energy improvement initiatives on the existing property asset, such as the energy requalification costs, the housing selling prices ante-energy intervention situations and those related to the post-energy intervention one, and the value differential between the two situations. The adequacy of the methodology is pointed out by its flexibility and user-friendliness, mainly thanks to the systemic logic-operative process defined through the illustrated phases.  
The case study of the present research concerns the Italian context. In particular, all the 110 provincial capitals located in the twenty regions have been considered. In order to define an evaluation model of the economic benefits, in terms of convenience of the operators involved, generated by energy improvement interventions on existing residential buildings carried out through the use of the Superbonus, the analysis has been developed with reference to the most prevalent (most common according to the ISTAT data [1]) building typology, i.e., multi-story building made of reinforced concrete, and by considering the main urban areas in which each provincial capital is divided (central, semi-central and peripheral). In particular, for each urban area of the Italian provincial capitals analyzed, the market value differential between the post-energy intervention and ante-energy intervention has been firstly determined by comparing it with the energy requalification costs (i.e., considering the situation \"with\" and that \"without\" the incentive of the Superbonus). Subsequently, by assuming a unique profit margin of an ordinary entrepreneur interested in this type of investment, for each area, the break-even incentive has been estimated, i.e., the percentage threshold able to ensure the condition of minimum convenience for the investor.