Blower Door Test - Meaning of the Result

When is the Bloßer-Door-Test usually conducted?

Very different, depending on the construction company. We had him after the shell construction, the exterior was not yet plastered and the interior walls were not yet closed. Of course, the windows were already installed. The construction manager's statement was then: with this result, he knows that his guys did a great job. Afterwards, construction continued.
However, there are also cases where the blower door technician comes several times until the desired value is reached because there is too much leakage in the house. Annoying when the exterior plaster and the interior walls are already finished...

Do actually everyone do this Blower Door Test? Or only if it is required by the KFW or someone else?

We build quite "normally" and I wonder if I should spend 500?€ on it.
Obviously the values are only not achievable if there is drafts like crazy, and I would notice that even without the test.

What is normal? If you have a controlled residential ventilation system, I would do one. At 1.5 and worse, there is no draft like hell. For many companies, values around 1.0 mean that something is wrong.

Hello everyone

a few answers to the questions
When to measure? It is quite clear that the B measurement is better for the building and its later use:
shell construction finished, interior plaster finished, foils without claddings finished
various main doors can be missing.
In this condition, leakages can still be fixed cost-effectively.
The cost of a measurement of about €250 is disproportionate compared to finding out "something is wrong" in the finished house.
Increased heating costs, mold formation, drafts
See the measurement as a quality control of the construction management

I would like to dig up the thread again here.

We have now received our result: 1.36. The measurement was taken shortly before moving in. We have a ventilation system, but it is not yet operational; the wall openings for the fresh air and exhaust air have not yet been made. Exterior plaster in the basement is completely missing.

Do we need to be concerned? What is the connection with the better required value of 1.5 with [Lüftungsanlage]?