You’re writing as if we should rather start a 450 thousand euro project from scratch because otherwise we’ll drive it into the ground (change architect).
That’s how it is.
1. Placing entrances in the corner has never proven successful.
So certainly not exactly stylish but also certainly proven.
2. There is nothing at the bottom. With a uniformly 2/4 winded staircase, the user has an even rhythm when walking. That is important so you don’t stumble or step into emptiness. Unfortunately, that is not the case for you.
It’s nice that you as a layman are thinking about the staircase. But half-knowledge is often dangerous or negligent. I can hardly believe that the architect voluntarily plans this construction. The hallway/hallway area alone is suspicious and only restricts.
The two quarter turns are always at the bottom.
3. Your hallway construction uses more space than a normal entrance. We don’t need to talk about 8x8 houses here, this is about yours.
Unfortunately, I cannot follow your arguments. I have the feeling that you are partly going off track. For example your roof: completely okay, this 45 degrees, but then not with a loft bed, or open upwards. That means 10 meters height with 10 meters width. Or have I missed some info in the meantime? Then forget my remark.
I would like larger staircases and hallways, preferably 2 times 100sqm, ... but since the footprint is supposed to be limited, that is our compromise. Yesterday I saw city villas again with 2 full floors and only about 8*8m external dimension.
And yes: at 450000 I would leave all of that freely to a professional and not tinker around myself.