Use of an expert system rating for the energy performance of a building

n this paper we present an expert system for the energy performance evaluation of buildings. The system is obtained from the integration of different evaluation methodologies in a unified framework and results in a friendly tool made available to internet users, who can obtain, in real time, good quality performance certificates. The scope of the project is to develop a performance assessment of buildings that is both complete and flexible, and that could be extended to different environmental conditions. The project has been originated from the official European procedure EPBD 2002/91/CE which states the essential requirements in a performance-based building strategy. The expert system designed in the first stage of the project has been embedded in a software tool named BEEPS (Building Environment and Energy Performance System), where a Life Cycle Analysis technique is implemented to provide a material and energy balance over the entire life of the material, product or service. This embodies the knowledge of experts in energy evaluations and makes such knowledge available to users in a comprehensible and concise way. A dynamic set of rules processes the data on the building, draws the proper conclusions and constructs a certificate in textual form combining analysis, motivations and suggestions to improve the energetic efficiency of the considered building. The system has been customized for the production of energy performance certificates of buildings in Italy, taking into account climatic conditions, indoor environment requirements, and cost-effectiveness. Residential premises and winter have been considered in a first stage. In the paper we also describe the validation of the proposed tool on 120 case-studies related to residential real estate built in Rome during the last century. Additional components of the project that strongly contribute to the effectiveness of BEEPS are also described, such as the analysis of the building typology and the use of the Geographical Information System for data gathering. The full system is currently available on-line at www.beepsitalia.it.