Thermally insulated walls will not suffice to save energy. To achieve high insulation levels one needs to ensure your home is air tight
Air tight like a thermal flaskEach intelligent house has thermally super insulated walls. Just like a thermos flask. If you forget to close the lid, warmth/coolness will escape. This is because there will be heat exchanged between the internal air of the flask and the external air.
With ICF/PIF/styrostones you'll have a complete outer envelope that is thermally super insulated. However how can you be sure, that it is airtight and your insulation efforts are not in vain?
According to Part L of the Building Regulation from July 2008 (IRL, UK), § 6 of the EnEV, SIA 180 and ÖNORM B 8110-2 buildings must be constructed permanently airtight
A blower door testcan prove the level of airtightness for you. A blower door is a device consisting of an adoptable frame, that can be fit into one of your doors. In the centre of this device there is a fan with which air can be blown into your house to increase the air pressure inside your house in comparison with the outside world. The loss of pressure, measured by manometers, over a certain period of time gives an information about the air tightness of your home.
If you need an energy performance certificate for your house, a blower door test will be a part of the preconditions you have to give, before this certification can be issued.