Air-to-water heat pump sizing in new construction

Right, so should I find the weakest link, i.e. the room, in the heating load calculation? How do I find this?

Right, so should I find the weakest link in the heating load calculation, namely the room? How do I find this?

What kind of calculation did you get?
Are there any under- or overcoverages indicated?

Until we decided on a wall heating system, for example, the bathroom showed a shortfall [W]: 353
In the widely used Excel version, it then says: overcoverage [W]: -353

What kind of calculation did you get?

This is how it looks for us. Which room would be problematic?

This is what it looks like for us. Which room would be problematic?

Overall, it looks quite balanced.
The hallway is clearly overheated, but that can be regulated by throttling.

Underheated is actually only the guest room, so you can improve the forward flow with the floor covering. ;)
Then comes the bedroom, where one degree less wouldn’t bother me either.
And then living/kitchen, and after that we’re already at the bathroom, which has probably been somewhat "softened" here because 22 degrees were chosen instead of the usual 24.

Thank you for your assessment. The bedroom is also throttled, 21° is too much for us.

Is the location of the room (proportion of exterior walls) also taken into account in the heating load? What rated output does your heat generator have?