Blower-Door-Test result (n50=1.13)

Hello dear forum,

We are building a prefabricated house with a ventilation system. Today was our BDT and the result was n50=1.13. The construction manager said that it is within the standard (max. 1.5). Regarding the circumstances: The envelope is in place, but the skirt is still missing. So the material(?) that is glued to the floor slab.

What do you think of the value? As a client, do I have the option to demand that the value be improved?

Thanks and best regards

As a builder, do I have the possibility to demand that the value is improved?

Why? It's in the standard! At 1.13, well below that. If you want to achieve passive house standard, you would have had to build accordingly.

All good, don't worry!

You cannot demand a better value, but you can demand that defects be eliminated. For us, it was also checked exactly where the leaks are.

I had similar values and made everyone appear again for a second test to discuss defects. Of course, no one was interested, and those involved suddenly got creative: "it's passed anyway, the rest will be fixed by the painter, drywall has to be airtight, not the vapor barrier" and other stories.

The value is not particularly good, although I don't know how much a fabric apron affects it. More important than the value is whether there are any defects. Later on, you won't have access anymore.

A possible starting point is the calculated air volume used in the test - according to my expert. If you calculate precisely and use the actual interior volume instead of the rough value from the energy certificate, the test could also be considered failed.

Thank you for the answers.

The team went through every room with us during the negative pressure measurement and checked all the corners. The statement was that everything is sealed.

They suspect that it could either be due to this apron or the chimney?!

Would you not worry about the value?

An unfinished raw wall without interior plaster behind the WC pre-wall and WC actuator is still a common cause of leaks.

You either have a huge hole in the wall somewhere, or they maybe just forgot to tape off the chimney.