Annual based performance analysis of buildings thermal insulation

The paper reports an overview on the physical basis of the building thermal energy balance finalized to make in evidence what are the principal energy flows which can be influenced by the envelope insulation degree. With the goal of minimizing the energy need the building thermal load is clearly defined and its minimization is identified as the driving key to reduce the required yearly energy demand. An extensive although simplified analysis on the thermal load components is carried out to identify how they react to an envelope insulation change. The results show in some components different and opposite trend with increasing insulation between heating and cooling seasons, which make impossible to have a general response for any building in any contest and climatic conditions also on national basis. General conclusion is that a real building energy optimization is requiring a yearly energy performance parametric study for this specific building to tailor on the specific contest and climate the full set of governing parameters other than insulation.