you are building in Thuringia? Just out of curiosity, in which area? As a fellow Thuringian? I want to pick up the basement discussion again. Basically, it has already been said... You want to keep the footprint of the house small because the plot is small. If you now move "living spaces" to the basement, you have to sacrifice space for slopes and light wells - which again reduces the garden! - and you have a huge effort to bury the basement because the plot is level - and that's considering a limited budget. To me, that doesn't make sense at all, honestly. I have a friend who I occasionally visit and sometimes stay overnight. If her husband is not there, I can sleep "upstairs," if he is there, I get the official guest room in the basement. And sorry, even just for sleeping... it’s a basement, with a light well, it smells like a basement and you go through the "utility rooms" on a concrete floor... the ambiance is not pleasant, even if I only pass through once in the evening and once in the morning. And at the latest when I wake up in the morning, I feel rather uncomfortable. So I'm also not pro guest in the basement, and for working there, I wouldn't want that at all. By the way, I also have a mini plot, 306m², and a detached single-family house on it. Since it's only supposed to be enough for three people (two children and me), 100m² is sufficient. With your 50m² more plot area, you can surely get 50m² more living space with good planning and there will still be a bit more garden. Be brave! Keep the living spaces above ground!