ᐅ Blower Door Test Result (n50 = 1.13)

So initially, they tested everything using negative pressure. The value was around 1.4 or so. Then they spent about 2-3 hours checking everything, sealing everywhere, and filling some gaps with foam insulation to make it airtight.

In fact, they went through each room twice and tested every gap and joint.

Still, quite a few things are missing.

- The skirting board at the floor was bulging, meaning it had holes.
- The window sills are missing.
- The house apron (the protective external base trim) is missing.
- The chimney was taped off but not completely; it will be covered with OSB panels on Monday.
- And so on.

I’m not sure. Can I still insist on a further defect search? How would you proceed? I’m here to get some advice.

You have enough explanations showing that the value turned out somewhat higher than desired.

What do you gain from a different value?
It’s like with your final exams: later on, no one cares about your exact grade, only whether you passed.

What you’re saying doesn’t make sense... The airtightness value isn’t meant to just fall below some theoretical limit so you can get money from the KfW; it mainly shows where air leaks into your house, which costs you energy... So the value should be as good as possible.

To keep the comparison with the high school diploma: I have a 4.0 GPA, but that doesn’t mean I can do math...

So now you have some clues about what the problem might be, and these need to be fixed, which your general contractor seems to be trying to do.

Oh wow... we had the test yesterday.
KfW55 construction method.
Our value was 1.4!

According to TÜV, the cause is the electrical outlet inserts, the base is not yet glued with perimeter insulation, and the front door did not close properly due to a missing lock (power was off).

But 4 minus! Passed is passed.

The defects will be fixed later.

So, airtightness issues due to missing perimeter insulation – about as reasonable as saying "it’s raining inside because the drywall hasn’t been plastered yet."

We were told that the test is done before the insulation is installed, so that any errors can be corrected. The insulation does not have much effect.