Second residential unit in the house due to KfW funding 153

The thing with extra insulation (sound?) applies to apartment buildings, but not to multiple residential units in a single/double-family house.

Where does this misconception come from?
The introduced technical building regulation according to the state building code for this is DIN 4109. This concerns sound transmission within multi-story apartment buildings and single-family semi-detached and terraced houses.
As soon as there are 2 residential units of any kind in a building, 4109 is the absolute minimum. Therefore, possibly additional construction effort compared to a pure single-family house, since there is no sound transmission between different residential units there.

Your headline is wrong and must read:

KFW funding 153 because of a second residential unit in the house [emoji2]
You don't build something because of a subsidy that you don't even want and fleece dear old Father State!

Your formulation is incorrect .

It must say: [...] and thus exploits all taxpayers.

Well, that goes too far.

Where does this misconception come from? The established technical building regulation according to the state building code for this is DIN 4109. This concerns sound transmission within multi-story residential buildings and single-family semi-detached and terraced houses. As soon as there are 2 residential units in a building in any way, DIN 4109 is the absolute minimum. Therefore, possibly more construction effort compared to a single-family house, since there is no sound transmission between different residential units there.

So first of all, this is neither about multi-story residential buildings nor single-family semi-detached or terraced houses. Furthermore, the KfW defines for itself and its funding program what is to be understood as an independent apartment, and these criteria are significantly less extensive than the regulations you mentioned.

"An apartment is considered a self-contained dwelling (separate entrance, cooking facilities, running water, and toilet) that is suitable for and intended as a permanent residence."

The key point is the separate entrance, which cannot just be easily created when a floor in a single-family house is to be separated in this way. This requires more apartment doors, a shared corridor, and/or the like.

Anyone who meets these criteria has no need to feel guilty or expect prosecution because they have simply fully met the funding criteria. Even if some do not like this subsidy.

which is suitable as a permanent residence and is designated as such.

With that, Alex is back to the great definitions. Who decides whether a residence is designated as a residence? Please consider the causal chain behind it.

I know plenty of people who planned (and also executed) a second housing unit and were therefore able to claim funding two or three times. But in my opinion, if you say A, you must also be able to say B. It must, as you yourself say, be suitable and designated as an independent residence.

Hey,

we are currently building including a 2nd residential unit - which is necessary at the moment - but if no one is supposed to live there and you just want the subsidy, you should definitely consider the extra effort.
For example, we really had to implement a certain amount of additional soundproofing in the granny flat, which didn’t have to be included in the KFW application, but had to be in the building application.
Not to mention the 2nd bathroom, the connections for the kitchen, the separate meter, and the front door.

Certainly, all these things don’t cost the full 100,000 you receive, but it’s not free either.

For us, it was only important that we are not forced to rent it out if our roommate is no longer with us and the kids have no interest.