A sensitivity analyses approach on an Italian case study: the simulations as tools for the design process

The early stages of building design include a number of decisions, which have a strong influence on the performance of the building throughout the rest of the process. The sensitivity analysis approach was applied with the aim of analyzing the influence of technical parameters on the energy balance and building performances. The parameter values and assumptions of any model are subject to change and error. Sensitivity analysis (SA), broadly defined, is the investigation of these potential changes and errors and their impacts on conclusions to be drawn from the model. A case study of a residential building is presented as an example of the adequacy of timely analyses of building performances, based on a preliminary architectural design. A virtuous combination of a receptive building owner and a multidisciplinary design team, allowed a systematic methodology to be used, providing the opportunity for the consideration of several options for each class of constructive element and the possibility of choosing among the options for each case, based on quantitative results on the expected performance of the building. The options were analysed with the help of one dynamic simulation tool IDA ICE and one steady-state CENED PLUS, aiming at a comfortable and energy efficient building. Several parameters were used for enabling the sensitivity analyses, namely relating to wall and window frames U-value, percentage of opaque and transparent façade and HVAC system, etc.