ᐅ Blower Door Test Not Conducted During Construction – What Now?

Created on: 11 Feb 2014 16:13
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Sanguinius
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Sanguinius
11 Feb 2014 16:13
Hello everyone,

I have a delicate problem—or maybe not, we’ll see.

The construction of my new condominium (3 units) is nearing completion. Everything went well so far, but once it came to the finer details of interior finishing, problems started...

For example, the vinyl flooring was installed first, and then work began on chiseling, drywall, tiling, and painting. You can imagine how the construction dust and debris affect the floor...

My biggest issue, however, is that we had the building constructed to KfW 70 standard. This is also stated in the construction description. The developer seriously claimed that a blower door test is not necessary to measure and verify airtightness for a condominium. The bank had a different opinion.

After overhearing some conversations among the tradespeople, with dialogues like: “Do we have to use this or that foam because of the blower door test?” I’m seriously concerned that these considerations might be coming in too late.

What happens if the KfW 70 airtightness is not met? Do you have any suggestions on how I should proceed in this case?
Der Da11 Feb 2014 16:26
What does the contract say? Did you purchase KfW 70 standard?
If so, the builder must continue to make the necessary corrections until your bank is satisfied.

Has a blower door test (BDT) been conducted?
Or did they run out of expanding foam and just stop?
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Sanguinius
11 Feb 2014 19:31
The contract states construction compliant with KFW-70 standards...
I only caught the part about the foam briefly.
The blower door test (BDT) is supposedly scheduled for the next few weeks.

However, no one wants to give me a specific date. I want to be there to ask the inspection team questions and so on.
How long they can make corrections is uncertain; the contractors seem to be doing only the minimum required and are being paid irregularly. This likely indicates financial difficulties.

Is it possible to manipulate a blower door test like that?
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nordanney
11 Feb 2014 20:05
For the KfW, a BDT is not strictly required! However, to my knowledge, the thermal insulation calculations are done somewhat differently in that case.
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Sanguinius
11 Feb 2014 20:12
The blower door test (BDT) is not mandatory, but the airtightness test is required.
In my opinion, the BDT is just one way to carry out such a test.

The technical guidelines for the KFW program 153 mention something about measurement-based proof?!
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nordanney
11 Feb 2014 23:02
That is not entirely correct. As far as I know, the reference house according to the Energy Saving Ordinance is calculated as a sealed building. Paragraph 6 provides more details, but only professionals really understand it. If using BDT (Building Dynamic Thermal simulation), then better values can be achieved ==> summary. We also reach KfW 70 without BDT, and of course, we address other aspects such as a ventilation concept.