Unequal width in the planned semi-detached house

I have attached the site plan with property dimensions. The left one would be ours. Including garage (6m) or carport (5m), there are still 8 or 9 meters width left.

Is that actually located in a geNORDet? And where is the street? What is that square protrusion at the top left of the property?

So, I sketched out the property with parameters. Actually, as an opponent of underground rooms, I would still be in favor if there is a desire or necessity for a basement. Because what use is a newly built house if it is not sufficient? But: with the dimensions of 10.2 x 9 and 40 cm exterior walls (Danwood apparently plans with 38 cm walls?), I come to just under 150/155 sqm. That should actually be enough for a 4-person household plus a large home office (large is relative), right?! And if it’s not enough, you can still plan with a single-story extension or even a two-story bay window. Overhangs on the upper floor are also attractive.

We would ideally like to persuade the two to be smart and simply build with a basement as well

Personally, I would always want to avoid a basement. It only generates storage space. It wouldn’t be worth it to me. The question is also:

The basement is non-negotiable for us.

Are you actually planning to build with Danwood, too? You have to ask pointedly when the basement is non-negotiable whether you can even afford it. 155 sqm living space costs €465,000, plus incidental construction costs of €40,000-50,000. The basement adds €80,000 on top. Then carport, parking space for the children's vehicle fleet, and outdoor facilities also cost between €30,000-40,000. I would rather make something nice above ground for the €80,000 basement costs and invest in the kitchen and other things.

Is this actually oriented to north? And where is the street? What is that square bulge at the top left of the property?

Exactly, the property is oriented to north. So north on the picture is also north. :D If that was the question. To the north, adjoining the property, the street passes by. But it is a very quiet residential street. At the top left is part of the bulge for the cistern, which is overall 6x6 m.

You bet. "If the lottery fairy doesn't draw my numbers, I'll die immediately" – such a fatalistic attitude is unhealthy and will never have the power to force an alleged luck. By the way, you haven't yet commented on the slope.

I deliberately mentioned only the short meaning without long speech because a partial basement is possible but uneconomical. The distance must also consider the slope of the excavation pit, so the 2m would be roughly the lower limit (and your staircase would therefore be fixed on the side facing away from the neighbor, but it would actually be considerably cheaper on the "shared" wall side). This Pyrrhic victory really doesn't have to be. Rent space in a self-storage center if you still need time for sorting flea market / recycling yard. A basement for storage capacity is by no means without alternative.

If more house length is allowed, that would be easier, then you could deviate from profile uniformity in the extra length. But I don’t really see that as necessary here.

Honestly, I find this post not helpful at all... The plot is level ground, so no slope.
The basement is important to us, and we are trying to find reasonable options for it.
The current plan is either a) to discuss with the other party about "pulling down" a wall as part of their earthworks up to the end of our basement, or b) to quickly come to an agreement with a builder and planner and at least build the basement before the slab.

If you feel like it, you could copy or attach the text part of the development plan here (no links, they are not allowed). Then we could take a look at what is possible. If you have the money, I would always build with a basement. The plot is small, every square meter counts. And yes, it would be clever to build it before the neighbor. But that has to go very smoothly.

So, I sketched the plot with parameters. Actually, as an opponent of underground rooms, I would still be in favor if there is a desire or necessity for a basement. Because what use is a newly built house if it is not sufficient.
But: with the dimensions of 10.2 x 9 and 40 cm exterior walls (Danwood apparently plans with 38 cm walls?), I come to just under 150/155 sqm.
That should actually be enough for a 4-person household plus a large home office (large is relative)?! And if it’s not enough, you can still plan a single-story extension or even a two-story bay window. Overhangs on the upper floor are also attractive.

Personally, I would always want to avoid a basement. It only generates storage space. That’s not worth it for me.
The question is also:

Do you actually want to build with Danwood?
You have to ask pointedly whether, if the basement is not negotiable, you can even afford it.
155 sqm living space costs €465,000, plus additional building costs of €40-50,000. The basement costs another €80,000 on top. And then carport, parking space for the children’s fleet, and outdoor facilities also cost €30-40,000. I would rather do something nice above ground with the €80,000 basement cost and still invest in the kitchen and other things.

The living space would definitely not be 150 sqm, but rather about 135 with walls and staircases. It’s also partly about the fact that this is a really big project for us and we don’t want to deviate miles from our ideas and wishes when building a house. And we need the space in the basement. There will need to be space for 2 children’s rooms and 1.5 work rooms.
We don’t actually want to build with Danwood, but rather probably with a local contractor. We already have a rough cost estimate of about €530k for the project including the basement, but want to get several offers in the next few days. From another prefab house manufacturer (not Danwood), with whom we were already in contact before the concrete planning, we were offered €580k today. €550k would be roughly our pain threshold.