TGA planner difficulties, underfloor heating supply temperature + wastewater ventilation

So, I have received information again. The flow temperature is now designed at 38° because a lower flow temperature is not supposed to be possible according to calculations. Due to the central exhaust system without heat recovery, the calculated heating demand is also 45W/m². The bathrooms are now designed at 22° and are still equipped with an electric towel radiator, which is not included in the calculation.

The following information is available to me:

Room	Number of radiators	VA	Radiator length
Living room (ground floor)	3	15	95/117/106
Hallway (ground floor)	1	15	83
Guest room (ground floor)	1	15	80
Guest bathroom (ground floor)	1	10	43
Children's room 1 (upper floor)	2	5	132/138
Children's room 2 (upper floor)	2	5	148/156
Bedroom + dressing room (upper floor)	3	5	58/129/128
Bathroom (upper floor)	1	5	126

As a layperson, I would say that the heating circuit lengths are quite large, but I can’t really assess the effect. Additionally, all the long heating circuits are on the upper floor. Could the slope still have a negative effect here, or is this already taken into account? The bathroom on the ground floor also seems to me to be designable at 24°. Here, a VA of 5cm could be chosen directly.

Rather strange interpretation.

Why are the bedroom/dressing room so tight with three circles?
The same applies to the children's room.
Why is the bathroom only one circle?
Why is the guest bathroom a larger VA than the bathroom?

"Rise" doesn't matter as far as I know.

Is the house above, i.e. the roof, significantly worse insulated than the rooms below?

Why is the bedroom/dressing room so tight with three circuits?

Apparently to reach 20° room temperature. But it certainly will mostly not be heated.

The same applies to the children's room.

It is probably also necessary to reach 20°. There is even a minimal undercoverage (1W/20W). If three heating circuits were installed here, the heating output should improve, right?

Why only one circuit for the bathroom?

No idea, maybe to save heating circuits?

Why is the guest bathroom larger VA than the bathroom?

Probably also to only reach 22°.

Is the house above, i.e. the roof, significantly worse insulated than the rooms below?

It is a developer project, so I do not have insight into all documents, but that seems to be the case. It does not seem to be due to the exterior walls. Children's room 1 has only a small exterior wall and otherwise the wall to the terraced house as well as children's room 2. Children's room 2 has two long exterior walls. The different heat demand of the ground floor and upper floor is definitely noticeable.

It is probably necessary to reach the 20°. There is even a minimal undercoverage (1W/20W). If three heating circuits are installed here

Please add the desired temperatures as well as the over- and undercoverage, if you have them. None of this really seems logical to me.

I can no longer edit the table above. Originally, 24° was planned for bathrooms and 20° for the other rooms. This was changed to 22° for bathrooms and 20° for the other rooms to achieve a lower VA on the ground floor. I don't know about overlaps. Currently, I only have the info: Children's room 1, 1 watt underperformance; Children's room 2, 20 watt underperformance.

I'll leave the bedroom aside. Is the statement regarding the two children's rooms correct?

Dividing into three heating circuits would reduce the temperature differential and increase the heat input into the rooms. The same would then also apply to the bathroom.

The guest bathroom could safely be set to 23° and the flow rate reduced to 5cm again. It was already like that at 40° flow temperature and 24° target temperature.