Bungalow floor plan 160-170 sqm with basement

I wouldn’t have recognized the Vita Haus by Weiss. Great that you can combine the two plots and are allowed to build "only" a single-family house. Is the footpath heavily frequented?

No, according to the development plan it remains a meadow.. so no paving or anything like that... I don't think there will be much traffic there, since the regular clean sidewalk at our place is on the street..

is stated in the development plan.. actually applies per residential building.. But good idea, I'll ask again.. Thanks

Garage can be attached, but must be slightly offset... not in a straight line

It’s not about costs, and no one wants to take your bungalow away from you – you are entitled to both.

Nevertheless, the fact is that you inevitably seal a lot of ground area, take away plot space for yourself (and 660 sqm is not that big), and end up with the typical bungalow problems of a lot of traffic area and little light inside. The basement doesn’t make it any better... on the contrary: if it already doesn’t work properly on the ground floor, how should, for example, a light shaft or courtyard illuminate the basement interior? That will be a cave!

How about a Bungalow 2.0: a more elongated building with a steeper gable roof, and sauna, relaxation room (library), etc. in the attic? Possibly with an open space into the common room. If you want an L-shape, add a glazed flat-roofed cube that extends into the garden? This one on top as a terrace with a view and exit from the sauna? So downstairs "only" 120-140 sqm, and upstairs another 40-50 sqm of luxury from the parents’ bedroom and wellness? And thus significantly more of the beautiful plot with the beautiful view?

The Vita house is not a family home and has all necessary utility rooms on one level. The kitchen is well zoned.
As you can also see, the bungalow has plenty of window areas, making everything bright and friendly. Necessary areas like the dining area are flooded with light – contrary to your plan.
However, in my opinion, the Vita also has some drawbacks that don't have to be there. It is not barrier-free.

Thank you for the feedback...

The Vita was just the inspiration, which we liked a lot...
The windows etc. that I drew in are just scribbles... my main concern is whether the room layout makes sense... but that does not seem to be the case... also the drawn door dimensions were all done on the phone... I just wanted to see if it is possible, with the options allowed to us, to create a 4-room bungalow of this size in such a construction style and to have my room layout reviewed by you experts... Many thanks.

Is the floor plan optimizable or rather completely useless?

Especially in the self-planning phase, always draw all rooms with the existing or desired furniture to scale. This way you can most easily see where it personally gets tight for you. Does the bookshelf fit, the shoe cabinet, the dream sofa? In many floor plans, doll furniture is drawn in and the dining area fits in every motorhome.

Regarding your floor plan
Bedroom: Draw in a wardrobe in the size you want. And not "well, then the suits just go to the basement"
Guest WC in the private area
Family bathroom extremely large
Children's rooms are not in the private area at all. You always have to go through the large hallway. For that, the orientation of the bedroom would be better. K2 a bit dark
The open living area is large but will not appear spacious and bright.
Hallway wardrobe directly at the door. Will almost always look messy.
Hallway to the basement, bathroom quite narrow and dark
Stairs to the basement will not be easily walkable.

I wouldn't have recognized the Vita house by Weiss.

Thank God not - compared to this model, one can almost speak of a "clear" design here, the Weiss Vita is hardly a corner bungalow anymore, but almost a convoluted bungalow. Besides, at mid-thirties and still with such young children, I would never ever think about the post-children time or even the "old age". Nobody guarantees you anyway that ailments will start precisely with osteoarthritis - so looking for salvation in avoiding stairs is rather a questionable wisdom. By the way, a fit ninety-year-old won't be sitting in a chair ;-)

Floor plan optimizable or rather completely worthless?

Definitely - not only the concrete floor plan, but already regarding the bungalow concept! - don't fall too much in love with it and first give the architect a chance. For the additional cost of the hip roof corner bungalow, you could have a car until the university entrance qualification.