Floor plan tube house L-shape triangular plot including oak tree

Now it's about evaluating the exorbitant offers from the construction companies...

What did the architect calculate?

I also really like it under your difficult conditions!

One can sometimes even be grateful for "erschewerten Bedingungen": even if originality probably wasn't the priority here, one still gets more of it "dank" the special circumstances than if one were to forcibly attach a bay window to their standard 08/15 plot Tuscan modernist house

I also quite like the floor plan, although I would reconsider the kitchen and rather allocate the tall cabinet space at the top right in the kitchen. Right now, it is more in the area to the right of the kitchen door.

And the space for the washing machine is out of the question... it could be planned in the drying room=laundry room.

I also think it turned out well. The laundry issue should be reconsidered.

And I would probably arrange the kitchen/dining area differently: the large dining table parallel to the big window and plan the kitchen as a two-line or single-line layout with a large island in front. I don’t like these corner kitchens in that size – it’s an endless running around. But that’s a matter of taste.

The 15% slope to the garage would give me a headache here in our area, but I think without a harsh winter with lots of snow, it might work. Definitely ensure good water drainage in the dip, otherwise the garage will flood during heavy rain.

Nice to see that everything is going to be fine now! Because you are allowed to get closer to the tree than originally feared, a well usable floor area has also been created! Overall still not ideal, certainly not cheap, but in the end a good solution. Good luck finding a construction company that is willing to deviate from the 0-8-15 rectangular floor plan.