The European Union aims to reduce emissions and achieve net decarbonisation by 2050. To support this goal, the Renovation Wave strategy aims to increase the rate of energy renovation of buildings. However, current assessment tools for energy renovation projects may not be accurate or consistent, leading to discrepancies between simulation results and actual building performance. A new energy study methodology using statistical methods to treat input and result data is necessary. This methodology simplifies the energy performance assessment process and the evaluation of energy refurbishment results. This article contains part of the first phase of this methodology which involves sensitivity analysis, which was conducted using three case studies from Spanish residential housing. Two types of analysis were performed: individual parameter sensitivity and Yates analysis considering parameter interactions. The results indicate that the methodology can effectively assess the sensitivity of buildings to various parameters and their combined effect.