ᐅ Is sound insulation according to DIN 4109-1 sufficient for a mid-terrace house?

Hello everyone,

I am considering buying a mid-terrace house in a new development. In the construction specifications under the section on sound insulation, it states that only the legally required minimum standards according to DIN 4109-1 are met. Furthermore, according to the construction specifications and thus confirmed in writing by the developer, the sound insulation according to 4109-1 is significantly below the high level of soundproofing usually expected in terraced or semi-detached houses, and noise from neighboring mid-terrace houses can be clearly heard.

According to homeowner literature, the minimum requirement under DIN 4109-1 for sound insulation is described as “loud speech intelligible, loud music audible” and impact sound insulation as “footsteps disturbing.” Additionally, the book advises against DIN 4109-1 and refers instead to VDI 4100 (2007).

Therefore, I assume that noise I generate (speech + footfall + TV/music, etc.) can be heard in the adjacent mid-terrace houses and vice versa. Would this mean that my neighbors would already be disturbed if my TV runs until midnight and they go to bed at 10 p.m.?

I am waiting for a response from an expert, but before that, I wanted to gather your opinions and experiences here in the forum on whether meeting only the DIN 4109-1 sound insulation standard would be a dealbreaker for buying this mid-terrace house, especially since I often work from home and my neighbors might overhear my confidential conversations and vice versa.

Here are the key data:
Ceilings L’n, w ≤ 41 dB
Stairs: L’n, w ≤ 46 dB
Ground floor party walls: R’w = 63 dB
Water installations L ≤ 27 dB (A)
Other building services equipment L ≤ 30 dB (A)

Partition walls between the mid-terrace houses are reinforced concrete walls, each 12 cm (5 inches) thick. Between the walls are separating joint panels, 4 cm (1.5 inches) thick.

I hope I am somewhat overestimating my concern and would appreciate any feedback, whether it confirms or contradicts my assumption.

Thank you in advance and good luck,
Twist21

Twist21 schrieb:

Partition walls between terraced house party walls = reinforced concrete walls, each 12 cm (5 inches) thick. Between the walls are joint filler boards, 4 cm (1.5 inches) thick.

Each house has its own external wall, with the joint filler boards in between. That already makes me feel quite reassured.

Twist21 schrieb:

when I often work from home and the neighbors might overhear my confidential conversations

That won’t happen anyway.

Twist21 schrieb:

Sound insulation according to 4109-1

That is the minimum sound insulation standard for sensitive rooms such as bedrooms, etc.

Twist21 schrieb:

a deal-breaker for buying the terraced house would be

How sensitive are you? You are getting a “standard” terraced house, as is built dozens of times every day. But even in detached single-family homes, there are forum members who say it is too noisy.

Would you like to say which developer it is?

Hi Benutzer200,

thank you very much for your quick response.

Benutzer200 schrieb:

Each house has its own separate "exterior wall," and in between there are the separating joint boards. That already makes me feel much more relaxed.

So are my concerns somewhat exaggerated, that the walls are "thin" and you can hear conversations? As a layperson, I am also referring to a builder’s manual that advises against DIN 4109-1, and the building specification also states that noise from other mid-terrace houses is more noticeable. That sounds like a legal disclaimer to protect the developer.

Benutzer200 schrieb:

That is the minimum sound insulation for noise-sensitive rooms, such as bedrooms.

But is the sound insulation sufficient when even higher standard requirements according to DIN 4109-5 or VDI 4100 are met in other mid-terrace houses, which the developer also mentions in the building specification?

Benutzer200 schrieb:

Would you mind telling me which developer it is?

Feel free to send a private message.

Good luck
Twist

Twist21 schrieb:

Gladly by PM

Unfortunately, I haven’t posted enough messages to be able to send a private message.

We have just moved into our mid-terrace house built in 2000.
According to the building specification, the partition walls are made of 17.5 cm (7 inches) calcium silicate blocks, with a 4 cm (1.5 inches) air gap, followed by the neighbor’s own 17.5 cm (7 inches) wall.
Unfortunately, there is no mention of sound insulation standards.
There is no basement.

We basically expected not to hear anything, but were a bit disappointed.
There seems to be a sound bridge to the neighbor on the right, as we can detect impact noise, which includes:
- Footsteps, but apparently only from certain spots/rooms (one of the occupants seems to have a rather heavy heel strike).
- A few times a day, a dull, short thud, as if something heavy is dropped on the floor.

Otherwise, we hear absolutely nothing. No conversations or everyday noises like washing machines, dishwashers, or similar.

Of course, it would be great if there were no impact sound transmission at all, but it is really tolerable and, compared to our previous apartment from 1978, a luxury.

I also work permanently from home.
The office is right next to the bedroom, and my partner currently has time off while I’m working.
The interior walls are made only of drywall, and you cannot hear conversations clearly. You can perceive sounds but not understand them.
So the neighbor definitely won’t hear anything – don’t worry.

Hi Hutchchinson,

thank you very much for your quick response!

Some opinions that relieve my concerns.

Hutchinson123 schrieb:

According to the building specification, partition walls are made of 17.5cm (7 inches) calcium silicate blocks, with a 4cm (1.5 inches) air gap, and then the neighbor’s own 17.5cm (7 inches) wall again.
Unfortunately, nothing is mentioned about the sound insulation standards.

Your walls are a bit thicker but made of a different material (17.5cm (7 inches) calcium silicate blocks vs. 12cm (5 inches) reinforced concrete). It’s good to hear that you have soundproofing.
I am still waiting for the expert’s feedback.

Hutchinson123 schrieb:

- A few times a day a dull, short rumbling noise as if something heavy is falling on the floor.

That could be the dog or an overfed cat jumping on the floor.

Good luck
Twist