ᐅ Prefabricated house, poor sound insulation / high noise transmission

Bookstar schrieb:

Where do you get your knowledge about the defects from? Did I miss something?

Snowy36 schrieb:

There is nothing mentioned about installation defects ...

With my comment, I wanted to point out that (especially in prefabricated house construction) the cause can be not only a component that was acoustically designed or selected incorrectly but also poor or faulty installation. And usually, nobody can identify this through data sheet remote diagnosis or as a layperson just by listening closely.

Snowy36 schrieb:

Now he is replacing the windows with higher sound insulation class.

He is not replacing the entire window but only the glass. The acoustic quality of the frame and sash, the sealing between the frame and sash, and the connection quality of the frame to the wall component remain the same as before.

Snowy36 schrieb:

I only know about bricks, and there the manufacturers specify the sound reduction index. So I should be able to check if a 70 dB noise is reduced to the stated 40 dB or not, right?

This is about a prefabricated house. Here, the execution quality is crucial for sound insulation; the acoustic ratings of the components themselves are of secondary importance.

Snowy36 schrieb:

That's cheaper than an expert report against pointless DIN standards.

You already asked for 800€ for a measurement. How much do new windows currently cost, say sound insulation class III or just the corresponding glass? I no longer have prices available.

800 euros was unfortunately JUST for measuring ... and then the statement: xdB ... everything else, like reviewing documents or inspecting the structure, I estimate will cost significantly more, but you should be able to assess that better, right?

And maybe the original poster can tell us how much a new pane costs ... I also estimate about 800.

Snowy36 schrieb:

I guess so

Before we start treating amateur "estimates" as facts, let's take a clear look at the facts.

Snowy36 schrieb:

800 euros was unfortunately ONLY for measurements

The expensive part of a measurement task is not the technician or the travel costs. By far, the most costly part is the use of the measuring equipment.

Snowy36 schrieb:

It will cost significantly more, but you should be able to estimate that better?

I don’t need to estimate that. A look at the Siegburg tables shows, even with a very generous assumption per building physicist, 100€/h (euros per hour). Many would probably do it for around 75€/h.
Reviewing documentation, plans, and records: half a day, calculated generously. If they inspect the site again: another half day. So roughly 800€, likely less when calculated with hourly rates. If you agree on a flat fee, they may work faster and cheaper.
With that, you get an initial statement on the cause, which can hold up until any possible court proceedings.
I wouldn’t want to rely on trial-and-error guessing, especially considering the financial and legal consequences of making modifications to a building that is still under warranty.

Many things can be figured out by using common sense, experimenting, and testing. It is not very productive to generally assume there are workmanship defects. First, focus on the facts and check what the structure is actually supposed to provide. If it becomes clear that the glass is, as is often the case, the weak point, then replacing it can lead to a significant improvement.

If you are still dissatisfied, you can bring in an expert.

Regarding the expert: the saying goes “he who measures, measures nonsense!” Caution is advised here.

Bookstar schrieb:

Assuming workmanship defects in general is not very constructive.

No one is generally assuming workmanship defects. The fact is, however, that workmanship defects in prefabricated house construction have a more critical impact on the overall acoustic performance than workmanship defects in solid construction.

Bookstar schrieb:

Glass is almost always the weak point.

Here we go generalizing again. Sure, glass is part of the overall window system. It is also the largest surface area component. But the frame and sash profiles are part of it as well, as are seals and connections to the exterior building element. Just think about the sound leaks caused by typical installation errors... mineral wool strips installed only on the room side, leaking joints, incorrect foaming around installation blocks, missing backer rods, glass with SF6 gas that has leaked out... The user Elefant can probably share some stories.

Anyway, the original poster has taken action and I hope it provides a solution. Maybe they will share an update in due course.

MayrCh schrieb:

No one is generally accusing poor workmanship. However, the fact remains that workmanship defects in timber frame construction have a more critical impact on the overall soundproofing system than defects in solid construction.

Here we go again with generalizations. Of course, glass is part of the overall window system. Naturally, it is also the largest surface by area. But the sash and frame are also part of it, as well as seals and connections to the exterior building element. Just the flanking noise caused by typical installation errors alone... Mineral wool strips installed only on the room side, leaking joints, incorrect foam application around spacer blocks, missing backer rod, glass where the SF6 gas has leaked out... The Elephant can surely share some anecdotes.

Anyway, the original poster took action and I hope it brings improvement. Maybe they will report back in due course.

Then a specific question on this:
And if the sound comes in through the frame, shouldn't you be able to hear that yourself? Use a stethoscope or similar to test whether the noise comes through the glass or the frame?

Because either the installation is massively wrong, in which case the effect would be significant, or it is not that bad, and then it can’t be installed incorrectly—or am I misunderstanding something?
Also, a blower door test should have revealed this already—I don’t know if the original poster had one, for example as part of KfW requirements or similar.