Building an end terraced house - Which technical requirements should be considered?

Well, the ratio of room to enclosing walls becomes very unfavorable. Either the staircase is perpendicular to the basement axis, then the basement floor plan becomes a T (and the aforementioned situation even more pronounced); or the basement dictates the staircase position (most likely single-flight straight, which is a big problem for houses under 12 m in width). There is one small way out: basement access from the outside.

Inefficient, since you still have the 2 long sides and only save about 3.5m of exterior basement wall at the front and back. On top of that, there are additional costs because the "split base slab" has to be made once for the basement and once for the non-basement part. For example, the concrete pump may have to make multiple trips.

Yes, this partial basement seems very much like a spur-of-the-moment idea to me

that a foundation must be laid in any case if the middle house builds the basement first, since otherwise our house with slab foundation would be crushed by the sheer weight of their basement.

He probably means that your slab foundation would have to be stepped down deeper than if everyone built without a basement.

Conclusion: it’s going to get more expensive anyway, so it’s best to build a full basement right away. Half a basement only shifts the "problem zone - step" away from the property line, to the middle under your house. The earthworks could be cheaper for both if a common pit is dug, right? I mean, then we’re back to the point “the middle house decides everything,” but there’s no use in that now.

Yes, this partial basement seems like quite a harebrained idea to me


He probably means that your slab would have to be stepped down deeper than if everyone were building without a basement.

I understood it the way I described it. There was no mention of stepped down.

I prefer the partial basement to the no-basement. Let's see how our general contractor plans it exactly.

Conclusion: it’s going to get more expensive anyway, so you might as well build a full basement from the start.
The half basement just shifts the "problem zone - step" away from the property boundary, to the middle under your house.

The earthworks could be cheaper for both if a shared pit is dug, right? I mean, then we’re back to the point where "the middle house decides everything," but there’s no use in that now.

Well... but from 7,000 for the foundation, which you might share, to a partial basement for 30,000 or 50,000 for a full basement, there are still quite a few jumps.
As I said—when the revised offer is in, we’ll see whether it fits our budget or not.
Building a house with blinders on is out of the question for us—it still has to stay affordable somewhere.