New construction of a semi-detached house with a full basement including demolition

Talk to a demolition contractor. Not one from MyHammer, but one who does nothing else. They usually can immediately see if and what is possible. They might also be able to give you names of architects who have experience with such projects.

But if it doesn’t work, we would move back 1 to 1.5 meters from the neighboring house.

That probably isn’t allowed. If it is a semi-detached house, it must remain a semi-detached house.

Our neighbor is an older lady, estimated to be around 60.

Yeah, the older lady is still working, so she is right in the middle of life with a lot of life experience. But that doesn’t matter. As mentioned above: architects can be found in the business directory. Thanks to Google, you can thoroughly search and check them from your office chair. Or you can ask around in the area about similar projects to find out who had their hand in it.

The Chambers of Architects also have lists of their members. In some regions, the list can also be sorted by [specializations].

I unfortunately cannot understand much of your joke/expression (@11ant), because my German is only just sufficient for everyday use.

Oh, that is a pity. I am actually very bad at "simple German," but I would like to try it once. So I will tell you the content of my previous post again at DaF level: Women "around 60" understand the term "elderly lady" only as women who are already older than themselves. So better say "elderly lady" only from age 75 onwards; around 60 "mature woman" fits better. You say your half is "no longer habitable" and "must be demolished." But you also say that the neighbor is apparently still satisfied enough with her half not to consider demolition. That surprises me because semi-detached houses typically have two equally good halves. So now I don't know: is your half just not nice enough to your taste, or really ready for demolition because it cannot be repaired with reasonable effort? A semi-detached house must be built without any gap between the halves. A little gap is not possible. Either the regulations for your plot say you must build directly adjoining, or the regulations allow you to build with a gap: then a full boundary distance is required (at least 3m per side, or in Baden-Württemberg 2.5m). But that would also apply to the neighbor. Since her house cannot be moved, you would then have to comply with her distance in addition to your distance, so effectively maintain a double distance of a total of 6 (or 5) meters. You write you would not plan an attic. But even under a low-pitched roof there is already so much headroom that it would not make sense otherwise. In the last paragraph I wrote to you where you can send me an email, and linked you to a post here: it concerns two service providers who find you an architect or plan a house. I myself am active with the one in Rhineland-Palatinate, and the one in Heidelberg has an engineering office himself.

I am sorry about my two points that were not explained clearly enough.

My neighbor should be over 70, but I cautiously estimated around 60. But yes, it is not important because I am always respectful to elderly people, so it was not meant any other way :).

The distance of 1-1.5m I meant the basement, not the house.

The neighboring house has been renovated several times. My house has never been renovated, was not inhabited in the last 5 years. My seller moved to Berlin, only used the house as storage. I have already spoken to two developers. They were on site, also said that the house must be demolished. However, due to rising material costs, they could not make me an offer. I have already been inside the neighboring house. Honestly, I personally find the house livable, but very uncomfortable. The ceiling is quite low. The plot is about 900 sqm. But the house only has about 4.5x8m building area. The staircase is also very narrow. It does not meet today's standards. If three people lived in the house, it would be cramped.

My consideration would be to forgo the basement, but really reluctantly.

The distance of 1-1.5m I meant the basement, not the house.

Oh, I see, yes, okay, that would be possible. To attach the house directly but keep the basement at a distance, that can be done.

But the house only has about 4.5x8m building area.

You should tell us more about that, or even better: show some pictures.