Consultant calculates price for 112m² KFW55 semi-detached house with basement at nearly €600,000

well, I think if two semi-detached houses are built simultaneously by a construction company, it will be significantly cheaper. [...] Only 1 portable toilet has to be set up.

Oh no, please don’t send the OP off now with the worn-out myth in April, that one could save a lot by bundled demand (in a batch size of 2 housing units!, *LOL*) or a saving on the cost center of rental toilets, that’s nonsense with pretty thin sauce! Semi-detached houses are not recommended for separate planning for much broader and far from only cost reasons – but you can hardly force a construction compulsion on your semi-detached partner. If they can afford to wait with their development, then so be it. But then don’t just worry about the temporary extra insulation of the later shared house side, but for example about the worst-case scenario that you build without a basement and the neighbor later builds with one. And of course read the story by – even if you don’t have a blatantly profiteering Schilda mayor: and by the way also would be my reading tips.

I think there's a misunderstanding here. Sure, we could save money if we could build together. And sure, we would have more planning security... but the neighbor has no interest in building at all. Her house is already on the property. She doesn’t need more houses right now ;).

Besides, the prices for a semi-detached house don’t shoot through the roof just because there isn’t one next door, right? Fire protection wall, insulation, okay. In return, we "save" a lot of windows on that side.

oh yes, and we are building with a basement. So that Mrs. Neighbor can add on more easily someday.

But why then a semi-detached house?

but the neighbor has no interest in building at all. Her house is already on the property.

Then you should illustrate the property situation once (cadastral map or aerial photo doesn't matter).

A semi-detached house is not more expensive than a detached house! Keep searching.

First of all: Why should a semi-detached house be more expensive than a single-family house? I don't understand... but I'm happy to be enlightened :D

So the price is totally exaggerated, to be honest.

For you to compare - since we build "relatively" similarly, just significantly larger:

160m² KfW 55 single-family house with heat pump and underfloor heating, 2 full floors, finished attic, with double garage, ventilation system, various equipment options like: electric shutters, windows with aluminum casing and lots of other "little stuff" --> also calculated turnkey
80m² utility basement WITH white tank

We pay 455,000€

If I had to guess, your house should cost around 350,000€ - 400,000€ - depending on the provider, quality, etc.