Single-family house 172 sqm with garage and sauna

Do you really want to squeeze a sauna into the narrow storage room next to the bicycle, lawn mower and so on? That has a warehouse atmosphere, but nothing of wellness. A bathroom as a passage room doesn’t work. Uncle Franz is really sitting on the shaft and the children come in.

Do you have another idea if the sauna should stay outside the house? Apart from an outdoor sauna

A double bed does not fit in the guest room.
The wardrobe is quite small.
If the sauna is downstairs, I would integrate it into the bathroom.

The bay window dining table just barely works.
Large dead space between dining and living areas.
I don’t like the kitchen. I would at least plan a peninsula.
Kitchen - terrace very far apart.

The sketched upstairs floor is better, but not good.

Outdoor sauna or integrated in the bathroom downstairs. This way it will never be nice and practical

350 euros/m3 is a thing of the past. In Bavaria, nothing really goes below 400 euros (more in urban areas). Such extras as [Kontrollierte-Wohnraumlüftung] are of course not included. In addition to incidental construction costs and outdoor facilities, there is of course at least a five-figure architect's fee...

What role does the architect play?

Our architect estimated 350€ per cubic meter...

I already didn’t come close to that in 2017....

The kitchen will not work like this. With 3.75 meters of shell construction, 3.70m remain. Subtracting the wall unit (65cm), main passage (110cm), passage by the window (70cm) leaves a smooth 1.25m width for the island.
So either get wider or scrap the island.
The route with the groceries from the garage through the storage room, WC, hallway, and utility room couldn’t be more cumbersome and longer.

Is the 60cm wide coat rack all there is? That’s never enough.

The situation with guest/WC/storage room is really not ideal.
The guest room—already not very big—becomes even less usable because of the “wart” of the shower.
A toilet as a passage room is out of the question, but that has already been explained here.
I would definitely scrap the access from the toilet to the storage room and move the shower into the toilet where it belongs. That would make the guest room usable, too.

If the sauna is still to remain in the storage room and accessible from the house, you could mirror the utility room with guest/WC and then go from there into the garage or the storage room.
As a shower option, I would then provide an additional shower in the storage room.

Upstairs, the hallway is simply way too large in relation to the rest.
What is the completely free area in the bedroom facing the bathroom for? Why not use it for the sauna? That would be my preference; then the topic would also be settled on the ground floor.

On the other hand, I find the walk-in closet okay and not too narrow. But only if one side has shallower (45cm) cabinets.
However, just for cosmetic reasons, I would move the wall between the walk-in closet and room 1 to the right, so that it aligns with the main wall of the hallway.
This would also make the walk-in closet about 40cm wider.

Sorry, but altogether there’s still way too much that’s off. Above all, the topic of finances.