Conversion of a two-family house into a duplex with complete renovation

So, a budget of anything under €500,000 would be desirable (but difficult, I know)....

Do you mean with semi-detached house a proper legal division? Like here the left half completely belongs to grandma and the right half completely to you? Because maybe you want to sell it later or why? Dividing out a granny flat or something similar would at least look much easier than making two proper semi-detached halves out of it afterward. And somehow that also seems a bit absurd, then somehow squeezing 4 people into a small space and grandma having the same/similar space alone?

What is your space requirement and what about grandma’s? Aka is she possibly happy with an open room (with possibly only a small kitchenette) + bedroom + bathroom or then totally unhappy because she has to part with way too much free space? And what about you, how do you imagine your house then? Open or rather closed? Do you need a study? etc etc. Also take a look here in the floor plan thread: Especially in the section Requirements of the builders

The shed plays no role here and can of course be removed.

Then I wouldn't have asked.

Unfortunately, there are no further plans of the house besides those already uploaded

At least in the building file.

I’ll take some photos of the house tomorrow, but I don’t think they are that important for the floor plan design yet, right?

Sections are always important for floor plan design (at least one, parallel to the gable), and yes, photos reveal a lot about a building’s condition. There are many experienced people here who can definitely make use of them (and less so without them).

@11ant Why always so unfriendly? Private problems? I ask for no further replies or “tips” from you, thanks.

I am not unfriendly, but merely have limited tolerance toward a “wash me, but don’t get me wet” lack of cooperation from questioners. You were already asked in the previous thread to provide the necessary information with your questions. You at least engaged with my tip regarding the entrance, but apparently took it the wrong way:

If a duplex is not possible from the start or a house with separate ground floor (entrance through 1st floor is out of the question), it won’t be a renovation anyway.

The entrance on the 1st floor level would be only one possible* option for separate house entrances – with more/better background information other solutions would also be conceivable. It’s really not understandable why you specifically reject the most feasible options (but absolutely want a duplex that is not possible here).

*) by the way, we already discussed such a solution a few years ago – I just can’t find the thread right now

What difference do you need between a 2-family house and a semi-detached house? Ground-level entrance for each apartment and a garden for each? Then demolition and new construction.

what difference do you need between a 2-family house and a semi-detached house? ground-level entrance for each apartment and a garden for each? then demolition and new construction.

Ground-level entrance as well as terrace directly on the ground floor. No shared staircase. The garden could also be separated in the 2-family house, but then I simply wouldn’t have a ground-level entrance and access to the terrace. Spiral stairs to the garden are unfortunately not my thing at all.

Do you mean by semi-detached house a real division? So the left half here completely belongs to grandma and the right half completely to you? Because maybe you want to sell it later or why? Dividing an apartment out of it or something similar would at least seem much easier than making two real semi-detached halves out of it afterwards. And somehow it also seems a bit absurd to squeeze four people into a small space like that, and grandma has the same/similar space alone?

What is your space requirement and grandma’s? Aka is she possibly happy with an all-in-one room (possibly only with a small kitchen unit) + bedroom + bathroom or totally unhappy because she has to give up way too much free space? And how about you, how do you imagine your house then? Open or rather closed? Do you need a study? etc. pp. Also take a look here in the floor plan thread: Especially the section requirements of the builders

Grandma currently has about 70 sqm, about 60 sqm would be enough for her. For us, it would actually be important to have 2 children's rooms, 1 small study or corner for home office. On the ground floor open kitchen-living area and small bathroom, ideally utility room (there is a basement as a technical room). Thanks, I will take a look at the floor plan thread right away.
We will probably join forces with an architect to clarify the basic question whether a two-family house can be divided into a semi-detached house or what role the existing staircase plays for the statics. Possibly the "old" staircase could also remain for part of the semi-detached house, nicely clad with wood and integrated into the living space. However, we lack the architectural and static knowledge for that.