ᐅ Blower Door Test – Meaning of the Result

Created on: 5 Jan 2018 23:51
A
AndreasPlü
Hello,

Today, as the final trade in our already occupied house, we had the airtightness test.

The result: N 50 = 0.68

We built a solid KfW 70 (2017) standard house. What does this mean? Is this good, acceptable, or rather mediocre?

Should we expect particularly harmful leaks? The tester detected a slight leakage at a sliding door but considered it within acceptable limits, which brings us back to the original question.
R
R.Hotzenplotz
17 Jul 2018 23:44
So, before plastering or only after plastering? For example, I can still see gaps between the bricks in the kitchen. These should be filled with the plaster.
H
haydee
18 Jul 2018 07:27
I would have said only after the exterior plaster, before the interior plaster and screed. After the exterior plaster, all the gaps should be sealed; you can still access them from the inside.

We had two inspections. One after the building envelope was sealed, before the screed and interior finishing, and one after moving in.
R
R.Hotzenplotz
18 Jul 2018 10:56
As I understand it, they want to apply the interior plaster first. However, construction is currently on hold. The site is deserted, and there has been complete silence for two days since the lawyer’s letter was delivered. I assume they are now reviewing their obligations and options.
H
haydee
18 Jul 2018 11:06
Probably. It's a shame it has to come to this.

The company we built with usually only carries out a blower door test quite late in the process. We have a passive house, so they play it safe. After the screed and painted walls, it becomes difficult and more expensive to make improvements. However, KfW does not recognize the first early test.
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Snowy36
20 Jul 2018 13:41
So if you only do one test, is it best to do it after the interior and exterior plaster but before the screed?
H
haydee
20 Jul 2018 13:49
Snowy36 schrieb:
So if you only do one single test, is it best to do it after the interior and exterior plaster but before the screed, or how?

Usually it is done shortly before handover. Our first test wouldn’t have been accepted by the KFW. We need to be better than 0.6. That’s why one was done as early as possible.
The second test for the KFW was carried out only after moving in and replacing the complained-about windows.
Not much has changed. Test 1: 0.42, Test 2: 0.35