Energetic Analysis of historical buildings by means of a typological research

According to the European directive 2002/92/CE, degree 311/2006, as from July 2009 all the existing buildings must equipped with an energetic certification to be shown when sold or rented. Probably this disposition, together with economic incentives made available for improvement interventions of the energy performances, will lead to a remarkable reduction in the consumption of energy attributable to the existing buildings. In Italy, around 40% of residential buildings were built before 1957, and about 78% of them are inhabited by at least one person. Therefore, for these kind of buildings it is necessary to either reduce energy consumption and to have them certified. The use of simplified procedures is therefore important for two main reasons in order to meet the above requirements: on one hand, to reduce the costs relevant to the issuance of the energy labeling (we count about 800.000 transactions per year, excluding rents), on the other hand to obtain indications regarding the consumption of energy which could promote improvement interventions to the existing real estate. Considering the variety of the stock building, it is therefore difficult to define simplified methods for the energy certification unless the buildings are first subdivided into homogeneous groups based on the period of construction and typology. This paper presents the investigation which has been carried out on medieval and renaissance buildings and which are still inhabited nowadays in the cities of Pisa and Pistoia. The aim is to define a correlation between the geometrical and energy parameters, representative of the identified typology. Such correlation and its subsequent classification is based on the investigation of the thermo-physical characteristics of the external walls and flooring, and on the modeling of the energetic behaviors resulting from the data deriving from the investigations performed on a number of flats.