Control floor heating

It's a matter of getting used to it, see Bieber for details.

It’s probably clear that you can lower the room temperature with an open window at an appropriate outside temperature. However, your heating will try with all its might to bring all rooms within the thermal envelope to the same temperature

Seriously, how do you come up with that?

I did not talk about feelings when I related the insulation values. I just didn’t give any numbers because there are so many different possibilities. An exterior wall made of 24 cm Poroton T18 with 140 mm mineral wool has an estimated U-value of 0.2; an interior wall made of 17.5 cm Poroton T18 has an estimated U-value of 0.8. The factor between them is 4. The temperature gradient important for energy loss at the exterior wall can be up to 30 degrees, whereas the temperature difference between rooms is just about 2-3 degrees. The factor between them is 10.

The conclusion is that energy exchange between rooms probably exists, but is not "much greater" than the energy exchange between rooms and the environment, and also not so large that different temperatures cannot be achieved.

You still have to take into account the different surfaces, the door, as well as the floor/[ggf Decken] (and thermal bridges). I have adjacent rooms in the basement that are unheated and they do not get colder than 16 degrees, even though I have not insulated much downwards either. For me, upstairs, without extra cold ventilation, I achieve less temperature difference.
From unterwegs