For a passive house, the maximal air-tightness of the outer shell is compulsory – air should not pass in either direction through tiny holes and cracks – often invisible to the unprofessional eye.

Scheme: Airtight building envelope of single family house in Lozen
One of the obligatory features of the standard is the air-tightness value of the building envelope. In order to be measured, a compulsory test with ventilators (n50) (Blower door test) is executed after finishing the building’s construction.
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Principle scheme for the compulsory for a passive house Blower door test
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Airtight gasket for plants penetrating the airtight building envelope, passive house, Munich
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Sticking a timber roof structure with airtight foils, Plus-energy house, Kladnica
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Sealing joints in order to achieve airtightness
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Testing of air leakages during a test with pressure ventilator
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Executing the first Blower door test in Bulgaria, Water house, Blagoevgrad
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Executing blower door test, Plus-energy house, Kladnica
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Ventilator of a Blower door test equipment
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Reporting a result from a Blower door test, Plus-energy house, Kladnica
Watch a video of the first Blower door test in Bulgaria for Waterhouse in Blagoevgrad with designer and project manager Studio APXE.