Dynamic simulation and on-site measurements for energy retrofit of complex historic buildings: Villa Mondragone case study

•Energy demand of a complex historic building is evaluated.•Dynamic simulation model with IDA ICE and on-site ambient measurements were used.•Calibration was made comparing monitored and simulated indoor air temperatures.•building retrofit solutions are proposed.

The paper presents a method involving on-site measurements and dynamic simulation to evaluate refurbishment solutions of an extended and complex building of great artistic and historical value, Villa Mondragone, located in the Colli Albani area and property of the University of Rome Tor Vergata. The approach has been successfully applied to a historic building of great construction complexity that was built during centuries, superimposing different construction technologies and styles. Masonry characteristics of ancient buildings are often hard to find and in situ measurements of thermal parameters (U-values) are time consuming, especially for large estates with structures of various superimposed ages as the case of Villa Mondragone. The paper demonstrates how a specific calibration of the dynamic model using only indoor temperature measurements can overcome this problem. The model was used to evaluate the energy performance of the actual use of the Villa and two possible cases of intervention. An improvement of approximately 40% in the energy demand has been evaluated adopting refurbishment solutions without impact on the historical value of the building. The model could be used also in the future to evaluate various refurbishment solutions not only regarding the envelope but also the plant and its use.