Static and Dynamic Evaluation Methods for Energy Efficiency in Historical Buildings VALERIA PRACCHI, Politecnico di Milano, Milano, Italia, valeria.pracchi@polimi.it RAJENDRA ADHIKARI, Politecnico di Milano, Milano, Italia, rajendra.adhikari@polimi.it ELENA LUCCHI Politecnico di Milano, Milano, Italia, elena.lucchi@polimi.it ELISABETTA ROSINA Politecnico di Milano, Milano, Italia, elisabetta.rosina@polimi.it This paper presents the comparative results of energy evaluation of two historical churches. The thermal performance is evaluated by means of static and dynamic computer simulations. The experimental data serve as verification of the thermo-physical parameters of the building envelope components for carrying out energy performance simulations: energy bills, temperature and relative humidity of air. In particular, the simulations are performed using the thermal transmittance values defined by Italian standards, calculated according to the European standard and measured in situ on several ancient buildings with different wall thicknesses and construction techniques. The present study aims to understand which energy audit schemes, more or less evolved, simulate better the real energy performances of the historic buildings and identify the strengths and the limits of each software for static and dynamic energy simulations. The final goal includes the need of intervening on a “particular” type of heritage to optimize the requirements of energy efficiency and effectiveness together with the preservation of their cultural values. An accurate diagnosis is the first step to identify the suitable intervention. Finally, the evaluation of energy retrofit obtained by dynamic simulation permitted to assess the real energy performance improvement and demonstrate that, in some cases, the conservative interventions have a proven effectiveness. Keywords: Energy efficiency, energy retrofit, historical buildings, computer simulations