Blowdoor test without informing the builder

Apparently, the test was done on the window in our case.

Which is supposedly good because a critical spot (the front door) is considered in the test.

whether the basement changes the value.

Since the result is the air change rate in 1/h, i.e. the quotient of leakage volume flow and room volume, one could assume that a large underground (therefore airtight?) volume makes the quotient smaller. So many windowless rooms increase the room volume (the denominator) but rather do not lead to leaks. As a result, the air change rate should decrease. Maybe someone who knows something about it will chime in... Or an expert with extensive statistics.

With us, it was done even without our presence. We then also received "the document" – and were satisfied. I have – and still do – trust in our craftsmen. The blow-door test was carried out by a contracted company – coordinating this appointment with the site manager and then also with the customer – I wouldn’t be interested in that either. I don’t consider the test itself an "important event" in the construction of a house.

we have a construction plan and know who does what when. nevertheless, I had to ask again directly about the blower door test. I was there then, it wasn’t super exciting. still a good thing, because you can talk directly to the measurer and he immediately points out where something is – and you can later check yourself if anything happened or not. our house was airtight except for one socket drill hole, where there was a slight draft. a bit of silicone later, the problem was solved. but it’s nice to hear directly and unfiltered from the expert that everything is fine. however, I wouldn’t start an extra test. the critical point is always the attic hatch, which for good reason is installed later :)

The critical point is, by the way, always the attic hatch, which for good reason is always installed later

Is that then a defect? So if a developer has the contractually agreed blower door test carried out before the attic hatch is installed, can you then complain and have the test repeated at the developer's expense?