Newly built condominium sound transmission

Good evening everyone,

I am new here and logically have a "small" problem.

We bought a condo in a building with 2 apartments through a developer. It was built to the Kfw 70 standard. We live upstairs on the first floor. We expected that such a new building would be better in terms of sound insulation than an apartment from the 60s, where we lived before. Unfortunately, after moving in, we had to realize that this is not quite the case. So we had the airborne and impact sound from below to above (which is unusual, yes) measured. These values showed that even the increased sound insulation standard is met. Nevertheless, the expert said that he himself did not expect this and that it is definitely not normal.

A brief overview of the noises to be heard.
- When lying in bed and it is quiet, you hear the neighbor doing his “little business.” The flushing afterwards as well.
- You can hear the faucet from below, just like the shower when it is quiet.
- The neighbor’s coffee machine, or when the beans are ground, can be heard in every room here.
- The opening of the blinds is extreme. Whether electric or manual. When they go up, we are awake too. We have already talked about it, but it hardly can be any quieter.
- Even the noises from the outside stairs, when someone goes up, can be heard.
- If you work on something in the garage, this is also transferred into the apartment. It is hardly distinguishable whether it is the neighbor below or outside.
- When the neighbors have visitors for a longer time, which fortunately does not happen often, there is no thinking of sleep. You hear everything. For parties we even make sure to be out of the house. And I find that pretty extreme...

In general, I think the outer wall is probably the problem. Everything is transmitted through it. If you knock on it, it sounds hollow and can be heard everywhere. As far as I saw, these are 36 cm bricks filled with some kind of wool. The two apartments are separated by a concrete slab and a flow screed. Unfortunately, I don’t know how thick the slab is. Is this normal? Are you allowed to hear this? Is there a chance to complain about it?

Another problem is the enormous heat in summer, which was denied to us upon direct inquiry before the purchase. He said it wouldn't get warm, that it is well insulated. A brazen lie...

I hope you have an answer ready. Many thanks in advance and have a nice evening.

That sounds bad and unusual. But if you already had an expert in the house, I wonder to what extent the forum can help? Especially with regard to a defect notification to the developer.

Hm, I would -- also with the help of the planning documents -- try to get to the bottom of the sound transmission (installation shafts ...).

The first assessor was a complete failure, the second was very good, but only for sound measurements, nothing else. The results were basically okay. However, he himself said that the result was surprising even for him. Well...

Now we’re not really sure what to do next. We don’t dare to file a complaint because we don’t really know what will come at us then. Costs, etc.

Somehow you still hope that it’s normal. But somehow not, because you don’t want to live like that.

We only received the documents after several requests and then only from the administration. I have to go there and ask for a copy.

Could this also be due to the plaster? Like that it transmits sound over the exterior wall?

The expert was just surprised. In writing, we only have the 2 results mentioned in the first post. The neighbors feel similarly. But they accept it as it is. However, we are generally very quiet and considerate. The neighbors are not, although it has been mentioned often. Next door, an identical building was constructed. The neighbors complain extremely there as well. Therefore, our perception is justified. The developer was present at the measurements back then. He says he is open to everything and only wants us to be satisfied. But of course, he denies everything. If you know him, you know that he basically doesn't care at all. Hypocrites without end. During the construction phase, we were even locked out because I complained here and there... rightfully so. These issues were then also resolved. We have a warranty of 4.5 years.

These values showed that even the increased soundproofing is being met. Nevertheless, the expert said that he himself had not expected this and that it is definitely not normal.
.

1. Before issuing a notice of defects, you must determine what is contractually owed. The case law of the BGH will help you with this. Just google: BGH increased soundproofing.

This concerns DIN 4109 in multi-family house construction, which is no longer sufficient today.

2. I do not understand the cited passage above factually. Then everything would have to be quiet..?

Yes, a box was set up downstairs that made noise and measurements were taken upstairs to see what arrived. The measurement showed an increased sound insulation. This measurement basically only simulates conversations etc., so airborne sound. Structure-borne sound, meaning the transmission of noises through the wall, was not measured because apparently there are no regulations for that.

The problem is that activities in the kitchen, which is on the exterior wall, can also be heard up here with us. You can even clearly hear the grinding mechanism of the coffee machine upstairs.

We could also have technical systems measured, such as the electric shutters. But we were already informed about the very high limit values that are almost always complied with. In other words, the measurement would be pointless.