Two adjacent buildings on a property - semi-detached house?

Good day, I have the following situation:

On a property there are, among other things, "two" solid houses.
House 1 was built first. After a few years, it was expanded by House 2.
Both houses share a common roof, attic (converted in both houses), have a separate main entrance and are only separated by a boiler room.

Can this be called a semi-detached house?

"and are only separated by a heating room" What is that supposed to mean?

And what is the background of the question? Is there a [WEG]?

"und sind lediglich durch einen Heizraum getrennt" Was soll denn das heißen?

Both houses have a ground floor and an attic. Between house 1 and house 2 on the ground floor, there is a boiler room in between, whereas the attics directly adjoin each other.

There is no WEG; there is only one owner.

That was even explicitly regulated by law at one point.

Definition as of today (and formerly in the Building Utilization Ordinance): Two houses built next to each other, but legally and in terms of development completely separated, on TWO plots of land.

In this respect, your question cannot be answered definitively. If both stand on one parcel, it is not a semi-detached house.

But these are all nuances. In case of doubt, state building codes and development plans are also important.

What is the background of the question? Actually, it doesn’t matter what name you give to the child.

The question is. Is the property divided? Then it is two semi-detached houses. Otherwise, a two-family house.

If the two are on one plot, it is not a semi-detached house.

Both stand on one land and plot.
Background: A residential building insurance for a semi-detached house is cheaper in my case than if I take out separate insurance for each house.