Are construction costs transferable to small houses?

No one is trying to talk you out of it, the small house. It just makes little sense if floated or flying homes are only slightly more expensive than an affordable standard bungalow from the budget providers. You will be happy with the standard one as well.

I am also rather critical of these houses for which there is even a new special term; that seems a bit too fancy to me. Therefore, I still like the simple design of the Thule KuBu in wooden post-and-beam construction. That feels more pleasant than a container house (ceiling height, open living space). But I have to see it on site next time when I have time. They also come with an extension of 60sqm-80sqm. 40sqm living space and 20sqm for everything I didn’t think of (utility room, fireplace), whereby the 40sqm KuBu partly has double ceiling height; that is almost more living space, I think, even if that is "just air without floor." If anyone has experience with such houses (40-90sqm), I am still very interested. Such experience reports are rather rare. I am constantly looking. The next step is probably to move from the big city to the countryside around the plot so that I know if I want to live there and so that I can carry out the demolition of the existing building (barn) where the house is supposed to go. So it will be quieter here in the thread for now.

The next step is probably to move from the big city to the countryside around the property so that I know if I want to live there and so that I can carry out the demolition of the existing building (barn) where the house is supposed to go.

A very sensible step. Had you mentioned before that there was an existing building?

"A very sensible step"

Yes, I agree!

Such experience reports are rather rare.

I don't have the experience of having lived in a small space for a long time, but from my point of view I would still like to say something about it:
After I moved into my own house a few years ago and found it difficult to commit to a living room with a "ridiculous" 22sqm, I have since realized: it always depends.

Friends of mine moved into a smaller house next door and are completely satisfied with it.
When I am "standing my ground" while cleaning (as I consider normal and right), I am always glad that it's not even more space.
I would still find a larger living area exciting, but if I look closely: when walking around daily, I don't notice it – and if it were smaller, it actually wouldn't be a problem either.
Feeling comfortable depends on so many details – and some of them can be intentionally influenced.
"But the neighbors have more space" belongs to these details and I believe envy influences us all far more than we admit to ourselves.
In Berlin many people would have more space, in Amsterdam I would be "the king" with my 22sqm. Keeping this relativity in mind helps.

I experience the difference between city and countryside like this:
What is cramped in the city, for example when there is no balcony attached to the apartment, is not as important in the countryside because there (provided you have some land around) you are outside a lot more anyway – or at least you can be.
What helps against feeling cramped – in my experience – is the space where you can move without having to coordinate with other people. The space doesn't even have to belong to you... it still relaxes.

At least as important as the available space is the location of the house. Nice neighbors? Beautiful area? Interesting surroundings?

A friend of my father – long deceased – said: I love the S-Bahn and that it rumbles past here. If it didn't exist, I would never have been able to afford the house at Schlachtensee ... :D

What I miss here in Northern Hesse, where I am, is the variety of enjoyable restaurants, but if my wife didn't cook well, I would practice it more myself ... :cool:

To sum up:
there is no useful good or bad but above all your own preferences and tendencies. You should look at those carefully beforehand.

Brief update: After some time off, I had some time and motivation again to deal with the topic. I unfortunately received no response from Thule, who offer the "KuBu," despite two inquiries regarding a viewing. Presumably, the provider is too small. I was on site at a model home park and was initially a bit unhappy because none of the houses appealed to me (all too big, made for families, not for one person). That stresses me out (-; Then I went to a more distant model home park and saw the Flying Space from Schwörerhaus in person and found it great in terms of size, quality, and the 4 double windows/doors on the south side. Accordingly, I had a sales meeting. Unfortunately, I only just learned that the KFW 55(EE) subsidy ends at the end of January. That means if I want to take advantage of the 30K (with a house price of maybe 160K), I would have to sign the offer that I receive in the next 1-2 days by the end of the week so that (without risk) all documents are ready after the company holidays in mid-January and I can apply for my subsidy number by the end of January. Another big downside: delivery time 18 months (fixed price 2 years). I had hoped to move in in 2022; the setup only takes 1 day, immediately ready to occupy. Because of KFW 55 EE, underfloor heating and air-to-water heat pump would be installed, split units (outside). My concern now is that the device is too loud for me. I already get stressed when I hear the street, but the device would be practically right in my garden. Does anyone know if the devices are noisy nowadays? Or if I can build a kind of wooden structure around it, if that helps?

Unfortunately, I only found out now that the KFW 55(EE) subsidy ends at the end of January. That means if I want to take the 30T (with a house price of maybe 160T), I would have to sign the offer that I receive in the next 1-2 days by the end of the week, so that (without risk) all documents are ready after the company holiday in mid-January and I can apply for my subsidy number by the end of January.

In theory. In practice, you would have to be immensely naive for that. So close to Christmas, no one with even a speck of sense would bet that the Easter Bunny reaches the goal faster.

In theory. In practice, you would have to be immensely naive for that. So close to Christmas, no one with even a spark of sense would bet that the Easter Bunny will reach the finish line faster.

You mean that the seller just wants to quickly collect a commission? He already said that we can also plan relaxed without the funding. But with 160K, 30K is something different than with 350-450K. (My opinion) According to the seller, KFW 55 standard (in some federal states 40) is no longer eligible for funding, according to the law. According to KFW, money should now rather flow into renovation (CO2 saving potential). I am aware that a one-person house is not really desired, so it makes sense that I can soon no longer expect a subsidy (from the state). Regardless, there are still cheap loans at the moment, which may not last forever. At 1% or similar, it would be more sensible to invest your savings and finance through credit. On the other hand, I am also glad when I finally have to get something moving, I feel like I have been dealing with the desire to build a house for too long, but without a deadline you take your time. Input/advice regarding air-water heat pumps and noise would definitely be interesting. Also, there is a slope south of the house. I will provide a picture later. I am unsure whether that is nice, regarding the view. But I have no other option anyway :)