Hello Ralf... a good idea your interchangeable house types.
Regarding the Blender files I would not need these at present.
My interest is fairly limited at the moment, as without other moving boats and tides in a scenery, there is very little realism, for the era that interests me of around 1800, etc.
Hopefully things may change later in year and I could then put more detail into sceneries, regarding variety of houses, farms. churches, people, etc for around 1800.
Had a look at your page of houses, etc and it certainly looks intereresting and you have put quite a bit of work into it.