Single-family house 172 sqm with garage and sauna

That:

Hm....now you have painted a little "P" in my eyes

contradicts the:

I have been reading diligently in the meantime

Enlighten us: what is the gimmick of a transit guest WC?

I recommend moving away from simply copying a template. As you can see, it doesn't work.

More likely from the cookie-cutter approach of a general contractor. Any independent architect would act in an advisory role (i.e., also dissuasive) if the client planned nonsense, instead of reproducing it 1:1. At least in the knee wall behind the bedroom, this should be evident even to laypeople, unless they essentially lack spatial imagination.

Regarding the toilet: we wanted to be able to use the shower in the guest WC also for the sauna area and to access the sauna from the house (without going outside). We found a steel door in the guest room (= sleeping area with potentially longer occupancy) even less attractive.

The knee wall in the dining room is the so-called abseite and is not used; rather, the lean-to roof for the dining room is led over it. If we build it in, we would have a knee wall of 1.85m there!

The transit toilet, as 11ant so nicely calls it, I also find hilarious! I've seen a lot here, but never this. Just imagine the guest sitting on the throne, the kids have (exemplarily) taken their bikes to the storage room and go through the transit toilet into the house – that leads to funny situations, at least you always have something to talk about in a nice group "remember when Uncle Fritz had diarrhea at our place and Tom quickly wanted to use the toilet from outside and ..." *roaring laughter* Nope, rarely seen something....uhhhhh....original like this! Once again, I'm missing the north arrow and I assume that the kids are sitting in the east or west, while the parents enjoy the south side. Why? I would redesign the entire upper floor and definitely move the washer/dryer upstairs. Variant 1 with the strange, unusable backpack at the master bedroom is wasted space.

Does the bungalow have a basement? - I would think twice about a deep demolition. With such a low eaves height, it will be tight for the garage to slip under the roof overhang without a problem if it is only one step lower. From the demolition, I infer that no infill development will be done here, but that the character of the area is to be preserved, so there are rather slim chances for exemptions that would go against this.

The bungalow has a masonry basement, which is damp and crumbly.
The property is staying in the family, and that is why we would demolish it.

Is the storage room planned as a sauna? Aha! Why not put the sauna upstairs? There you have a nice shower, a nice bed to rest, and space (e.g. in the unused "backpack" of the bedroom).

This:



contradicts the:

Our architect has calculated 350€ per m3...