Hourly-Simplified Calculation to Identify Cost-Optimal Energy Performance Requirements for the Italian Building Stock

The 2010/31/EU Directive established a comparative methodology framework to determine minimum energy performance requirements based on a cost-optimal approach. This research investigates the cost-optimal outcomes resulting from the application of the monthly quasi-steady state method (UNI/TS 11300-1) and the simplified hourly dynamic model (EN ISO 52016-1), both aimed at determining the thermal energy needs for space heating and cooling. The technical building systems have been modelled by means of a monthly steady-state method, in agreement with the UNI/TS 11300 series. The global cost has been calculated from a financial perspective according to EN 15459-1. The proposed methodology has been applied to two buildings that differ in their climatic zone, construction period, and intended use. For this purpose, a single-family house located in Palermo and an office building sited in Milan have been assessed. To investigate the deviations between the two energy models, the results in terms of packages of energy efficiency measures and global cost have been compared.