House planning 135m2 in Austria

That's Sweet Home 3D, right? You can edit the furniture there and enter your own measurements.

You do not generate heat in the bathroom unless you are currently showering or bathing. Bathrooms do not have a passive heat source (human) and solar radiation is minimal due to the house orientation. Bathrooms are usually exhaust rooms in a controlled residential ventilation system. In other words, the air is continuously extracted here. If you want it warmer there, you have to actively generate heat.

The extra insulation is not there for nothing and how should the exterior wall be designed flush?

If you want passive house standard, which heating concept is planned?

To your ground floor
The shower is very narrow
I still like it better that way

Pantry
Freezer doesn't fit in there, does it?
I like that better too

Kitchen
Not yet optimal. 80 cm of clearance to walk through is a bit narrow. Usually, your hands are full
I would align the row of cabinets flush with the wall and plan the row facing the dining area to be 1 m deep. It’s quite comfortable for rolling out dough when there is more depth

A double bed doesn’t fit in the guest room

You don't generate any heat in the bathroom unless you are currently showering or bathing. Bathrooms have no passive heat source (human) and solar radiation is minimal due to the orientation of the house. Bathrooms are usually exhaust rooms in a controlled residential ventilation system. In other words, the air is continuously extracted here. If you want it warmer there, you have to actively generate heat.

The extra insulation is not there for nothing, and how is the exterior wall supposed to be flush?

If you want passive house standard, which heating concept is planned?

Thank you for the explanation!
The "extra insulation" would have also been the monolithic brick in this case, which also forms the exterior wall. So the flushness would not have been a problem.
For the extra 1-2°C, electric heaters (towel warmers with blower) were considered there. That was a suggestion from a friend who is an installer. If it's not clear what I mean, I can gladly post a corresponding link to such a heater with blower.

A geothermal heat pump with a trench collector is planned as the heating system. If, contrary to expectations, that is not feasible on the property, an air-source heat pump will be used.

Austria is large - where exactly do you want to build? - 50 cm aerated concrete sounds quite high alpine

What insulation regulations do you have (do you know the Energy Saving Ordinance valid in DE and can say how similar your regulations are)?

The guest WC seems to me inspired by trains or motorhomes.

About your ground floor
The shower is very narrow
Still, I like it this way better

Pantry
Freezer won’t fit in there, right?
I like that better too

Kitchen
Not optimal yet. 80 cm to walk through is a bit narrow. Usually your hands are full
I would finish the row of cabinets flush with the wall and plan the row facing the dining area 1 m deep. It’s quite convenient for rolling out dough if there is more depth

A double bed doesn’t fit in the guest room

The freezer is planned for daily use underneath the refrigerator (fridge-freezer combo). For supplies and things that are not used often (fruit from the garden etc.), an additional cabinet in the basement is planned.
In the pantry, my wife really only wants to store supplies, so it is intentionally going to have no window in order to protect various foodstuffs from sunlight.
As mentioned, the whole kitchen is still in planning; I have passed this on to my wife now since she spends a bit more time there than I do—yes, cliché...
A proper, planned kitchen will follow soon.

The “guest room” is intended more as a “multipurpose room” rather than really for guests.
The plan is as follows:
- Mainly for the children (specifically our very little one, since the older one only comes rarely and not for much longer, and when he does, he’s just at the PC anyway), so there is a place where model trains or building blocks can be left out
- Storage for board games
- “Home office” in the form of a place to put the notebook and a cupboard space for the printer
- A sofa bed or “fold-out wall bed” so grandma can stay overnight occasionally if the older child happens to be home and his room is not available. But as mentioned, the older one rarely comes. Grandma comes even less often. Both at the same time only around Christmas…
We have even seriously considered omitting the guest room altogether, but then we would have to find another suitable place for children’s toys etc.

An architect we recently spoke with had a suggestion I’d like to put forward for discussion here:
A sliding partition between the guest room and the living room. Then the guest room would have to be planned next to the living room, but the room could be allocated to the living room 90% of the time and only partitioned off when someone really wants to sleep in it (or when guests come and the mess is too bad to show).
I find this idea basically exciting but I’m skeptical due to drawbacks (a wall that must not be obstructed on either side, sound insulation?)… What do you think?