I seem to remember that in the series "Traumhäuser" by BR there was also a house on a very narrow plot - just take a look in the media library. They solved it really cleverly!
But then it’s no longer a prefabricated house.
What I don’t quite understand yet is why a prefabricated house is so favored. It’s not necessarily faster than a local provider and in our case, the costs were only significantly lower with a prefabricated house if you took exactly the standard houses that the respective providers had in their program. Of course, many providers also plan individually, but then there is no cost saving anymore. And given the requirements of the plot, I would personally always prefer an individual, clever plan.
But that’s just my opinion.
I still think visits to model parks are good, you get a feeling for the rooms and can pick up ideas well.