Blower door test
A blower door test measures the airtightness of a building, or helps improve it in the construction phase. In the EPB calculation, the airtightness of buildings is automatically assumed to be 12m³/m²/hour, a very pessimistic assumption that is often not reflected in reality. If you have a blower test done, the real value can be used in the EPB calculation and often decreases the E-level by as much as 10 E-points. It is advantageous for you to have such a blower test carried out therefore, as it often results in a better energy performance certificate (EPC).