Single-family house or semi-detached house?

It’s best if you post an excerpt from the development plan first, then you can see more.

With a plot width of 13 m, the mentioned widths practically arise automatically (13 minus 1x 3 = 10 or 13 - 2x 3 = 7). 7 m wide and 14 m deep and everyone building a single-family house will look like the terraced house in the middle has been removed. This way, everyone can window both long walls, but the typical narrow-plan disadvantages of terraced houses’ towel-shaped plots remain: you hardly come up with many sensible floor plans with a straight single flight staircase. So it will be a typical terraced house, just with end-terrace-type windowing on both sides.

From one ridge direction along the longitudinal axis, if permitted, nothing good would come: the attic would then practically be the peak of a narrow shape. Two terraced houses with a gap between them also clearly look off-putting.

So I see it ending up with semi-detached houses. And if they are not planned in a coordinated way – actually even if they are, when they are not classic mirror twins – then hopefully at least a depth offset is possible. But even then it can look visually terrible if one is plastered and the other is brick-faced.

Semi-detached house plots are basically the domain of developers. Individual builders should, in my opinion, join forces here, and even if they don’t want a mirror twin, put a joint architect on it. Everyone building for themselves and thereby annoying the other is the textbook beginning of a (in the “best” case hereditary) garden fence feud.

From my point of view, you clearly found a semi-detached house plot here – even if a single-family house would be permitted there. A panda will not become a Ferrari, not even on the Nürburgring.

There is no classic development plan; construction should follow the neighborhood. It only concerns the two plots that are being newly built, around them are the gardens of other plots (which have long been built on).

My idea for a single-family house was to have more choice in architect and construction company, as I fear there will be problems if two companies build the whole thing, or does that work? - the other person has already decided on a construction company but is flexible regarding the house, clinker brick, etc.
Furthermore, my consideration was that a single-family house is worth more than a semi-detached house, or don’t you see it that way?
Also: with a 3m garage + 10m house width, I can only get into the garden through the garage or the house. How do I get to the bicycles, for example, do I have to move the car out every time?
For the semi-detached house, I was also thinking of a depth offset...

2 mistakes in your thinking:

if you place a 7-meter-wide house on a 14-meter-wide plot, you don't gain any advantage over a duplex because you are violating the property.

Who decides now that your duplex must be 10 meters?

And the third mistake: nobody says you have to stick your garage right next to your house; there are certainly other options, though few.

-> it's best to engage with the property by spending some time on it. Then you'll get a real impression of the area.

Best regards, Yvonne

If semi-detached or detached houses are allowed, the one who builds first also determines the conditions for the other: the waiver of the boundary distance at the municipal border is a matter of reciprocity. The municipality must be out of its mind to allow that without both plots belonging to the same owner. Semi-detached houses per se are not problematic, but allowing the freedom to choose between semi-detached and detached houses from separate owners is. The first interferes with the freedom of the other, making a trip to court almost inevitable. Experienced municipal councilors would never come up with such an idea.

The choice of house type determines the architect or contractor the least. Nor is a specific house type generally more or less valuable. Your smartest intervention in the value prospects of your property now is to make the best of the situation:

Accept the dice fallen for each semi-detached half, and look favorably at the contractor chosen by your neighbor. That is a good basis for the deal that he lets you have the first pick of the facade. Alea acta est - carpe Diem!

Yvonne is right to the extent that you do not have to use the full width: if you build your house only eight and a half meters wide, you will have one and a quarter meters left between the house and the three and a quarter meter garage.

Thank you very much for the helpful assessments. I will probably plan in the direction of a semi-detached house! The house builder chosen by my neighbor is also the land seller, a small entrepreneur (civil engineer/architect) who builds turnkey at a fixed price. He builds very high quality and individually. I also want to build very high quality, but I still find his initial price indications quite high: for a 2.5-story, ~200 sqm living space including basement and everything (i.e. outdoor facilities + garage, floors, etc.) he sees clearly > €500,000 (without land, development costs). However, a construction description from him for another project shows partially high prices: e.g., according to sample template: front door: €5000, interior doors: €500, flooring material: €100/sqm; garage: brick-built (if you choose cheaper, he naturally calculates against...)

How can I best assess whether a fixed price requested by him is appropriate? – He would probably do an initial planning according to my ideas free of charge and then make a price offer.

I thought about having a similar plan made by another house building company, whose construction description could possibly be enhanced by special wishes, and thus have a comparison, or do they not plan individual semi-detached houses? Are there other good ways to assess whether a price offer for building a house is appropriate?

The preferred house builder of my neighbor is also the land seller, a small entrepreneur (civil engineer/architect) who builds turnkey at a fixed price.

A brief side note. Be cautious with such arrangements. This may make the entire house subject to real estate transfer tax. If he does not act as a property developer, you may have to pay VAT and real estate transfer tax on the house.