Building Energy performance: how to choose a dynamic simulation program

Energy efficiency in Buildings, combined with an efficient use of the energy provided by renewable sources, are essential objectives set by the revision of the European Energy Performance of Buildings Directive. To achieve these objectives, an accurate estimate of the behavior of the system to be built/improved must be available during all stages of the design process or energy audit (if existing). While designing or improving energy efficiency, other important and associated goals must be ad-dressed, such as environmental health (hygrothermal, acoustic and luminous), costs, environmental sustainability, etc. Having to choose a dynamic simulation program to inform the design process it is necessary to analyze the possibilities offered by different available software, in terms of accuracy and completeness, while taking into account ease of use and included facilities aimed at supporting the design process itself. Over the past years, numerous Building Performance Simulation tools (BPSts) have been developed with the ambition of removing some shortages of existing BPSts in addressing today’s users’ requirements, sometimes by underestimating the reasons for those lacks of functionali-ty. A software improvement that is focused only on usability might oversimplifies the complexity of the model used by the tool, or its use, while a focus on rapid prototyping might respond poorly to the re-quirements of a certain typology of users. A critical review of today’s requirements and available tools is here presented, with the aim of informing a better awareness of possibilities offered or denied by current BPSts.