Combine two apartments

and because in old age you need a small single-story apartment and not a two-story huge place

I like to check in again later, but very briefly on this aspect first: forget it. Your generation will already regularly renovate rather than remodel in "old age."

[...] because when you get older you need a small ground-floor apartment and not a huge two-story place. As a young family, you can also climb stairs sometimes. The idea is that we will live on the ground floor when we get older.

When you get older, you also don't want to maintain an 800m2 garden anymore, which you can use so wonderfully as a young family with children. Many older people are also more afraid of burglars (for whatever reason), so apartments on upper floors are preferred – of course, these come with an elevator. I agree with , although I believe less that our generation will build again when older – but that they will afford a modern apartment with a nice balcony, elevator, and accessibility. Either as a rental from the rental income of the rented house or after selling it. Here in the neighborhood, six apartments of 100m2 each were built, very high quality and very expensive. These were sold to neighbors over 70 years old except for one.

You are right, it is easier to work with proper plans.

Yes, now I have the impression that more can be seen — not least the dimensions. I summarize what, in my understanding, is now the subject of the measure: apart from the modernization in the heating technology area (what is actually supposed to happen with the exterior walls, ETICS on them?), it is essentially about breaking through the ceiling in the children's room of the upper floor (as supported?) and installing an internal staircase in order to connect the upper floor and attic into a maisonette.

Right, that's what it's about. There is already a staircase that leads up to the attic. However, it is difficult to separate, for example without risking falling down the stairs right after the apartment door. Hence the interior staircase.

The room we sacrifice on the upper floor is currently a study or storage room. The wall between this room and the living room is to be removed, and the door to the study will be closed.

What do you mean by supported?

The exterior walls are not to be insulated. Aside from the discussion about whether it makes sense or not, the simple reason is that right next to the house runs the driveway to two garages behind the house. Currently, just enough space for one car passes through there. If you add 10 or more centimeters of insulation, the garages can no longer be used.

These are very interesting approaches to living in old age. Then I will have to look for something new for old age again. But instead of combining the upper and attic floors, combining the ground and upper floors does not bring me any added value? The ground floor is not renovated and rented out. The attic is not renovated and not rented out. The roof urgently needs to be done. So I take the upper and attic floors and still keep the 3 euros in rental income.

But instead of combining OG/DG, combining EG/OG doesn't bring me any added value?

With the newly submitted plans, I consider the question resolved, but generally I would always examine both options.

What do you mean by supported?

The reduced ceiling panel has to rest somewhere – is it a precast slab where entire elements can be removed for the staircase opening without affecting the rest of the ceiling?

It is a concrete ceiling. I would assume that it rests on load-bearing walls and on the exterior wall.