only a semi-detached house is possible, where the division is along the roof ridge.
You mean a zigzag roof?
There is such a thing. I once had one myself.
What do you think how unattractive your semi-detached house will become? It’s not without reason that you don’t find such semi-detached houses.
What do you think, how pretty they are and not as bulky as conventional semi-detached houses?!
The roof is not the massive roof, but each half visually stands on its own, usually with a gable view.
In our case, they were terraced houses, but the most beautiful and special ones in the whole community.
If you sketch what you exactly mean, then I’ll look for pictures.