Semi-detached house - Which one is the best? Who has experience with that?

This is all still in planning. But existing properties currently cost an "insane" amount of money here. (Empty plots unfortunately too)

* there are surely completely different areas / prices in the world

I'll shorten it for you. If you can't or don't want to afford an existing property in your area, then you won't be able to afford a new build either, because building new + buying land is more expensive than buying an existing property in the same region.

Don't be mad at me, but I suspect this thread is a waste of time, especially with regard to the KfW issue or even a passive house.

Thank you Zaba for sacrificing your time here... you definitely should not waste it on me!!

It is about the lowest possible consumption when living. And I see no way to make anything existing affordable in the way I imagine it.

For example, photovoltaics or ST can also be added. But not just to make the numbers look good...

If someone sees a reason to help me gather information, I am grateful for any help.

And I don't see any way to make something existing affordable the way I imagine it.

Well, but that is a problem. Building new is even more expensive.

What exactly is your plan, roughly speaking, when you have all the information together?

Isn't it perhaps even more sustainable to buy a used property, consume a bit more, than to waste many resources on a new build? I see it similarly to buying a car. Before I give up my old "polluter," which then continues to emit fine dust in the East, and choose a "clean" one made with a lot of electricity, CO2, and other resources, I'd rather keep driving the old junk...

Isn't it perhaps even more sustainable to buy a used property, to consume a bit more, rather than wasting many resources on new construction?

Absolutely. By far.

It's about the lowest consumption in living.

Those would be plus energy houses. Unfortunately, the production costs with all the bells and whistles are also the most expensive.

If sustainability in terms of materials is added, it becomes even more expensive.

And then economic efficiency is also clearly set aside. For the green conscience, you spend a lot of money.