[poseva]

I want to also to highlight the importance of the building airtightness (Air Changes per Hour) on the energy consumption needed for heating.

I saw an example at some point in one of PassivHaus presentation and it was like this:

0.3 ACH -> 1.74 kWh/m2year (for a 100 sqm house means, 174 kwh per year for heating)

0.6 ACH -> 3.49 kWh/m2year (PassivHaus limit)

1.0 ACH -> 5.81 kWh/m2year

1.5 ACH -> 8.72 kWh/m2year (Low energy house limit)

4.5 ACH -> 26.5 kWh/m2*year (typical house)

This is for the same house with the same insulation. Of course you cannot achieve this kind of airtightness without careful planning and using a lot of self-adhesive tape (SIGA, ROTHOBLASS and other manufactures that can guarantee its effectiveness up to 50 years)