Underfloor heating in the children's room? Some rooms planned without underfloor heating? Air-to-water heat pump removed?

If you have to heat 180sqm with a basement, a [Ringgrabenkollektor] would have a clear efficiency advantage over an air-to-water heat pump. For 1000sqm, I would strongly lean towards a [Ringgrabenkollektor] in your position.

If science says so, then show me sources

I also belonged to the "always open windows in the bedroom" faction. But with a ventilation system (always fresh air....) and underfloor heating (even temperature, no unpleasant radiant heat...), that's no longer an issue.

We have been living in a rental apartment with a central ventilation system for 5 years. We still sleep with the window tilted 90% of the year. That is still something different (for us)!

which brings us back to the topic. There are people who can sleep with light, there are those who like it pitch dark. There are people who need 15°C to sleep. There are those - like you - who can also sleep well at 20°C. But here I would like to bring science/medicine on board, which to my knowledge says that below 20°C is clearly more advisable in the bedroom. But to each their own

this is technically not possible in a new building. all rooms are within the same thermal envelope. even a completely unheated room is heated through doors and walls (which are not insulated).

our pantry has the heating off - I would say at most one degree colder than the kitchen next door, although the door is always closed and the heating is off.

since the kitchen has to heat more accordingly, because the pantry is indirectly heated by the kitchen, the energy savings will hover around zero... my wife just wants it that way, with the heating off in the pantry.

you won't be able to realize 18 degrees in the bedroom and 23 in the bathroom in a new building. you would have to technically cool the bedroom even in winter.

what you are trying to do here is transfer the actual feeling of an old building to a new building. then build an energy-saving regulation house with a gas boiler and window rebate ventilation; that's where you'll most likely get the old building feeling.

A lot has already been written and I thought you had already taken away quite a bit from the discussions yesterday.

As many others have already said, a system with multiple flow temperatures or a mix of underfloor heating + radiators, etc., makes no sense at all. It will cost you a lot and you will have to buy and install a lot of unnecessary technology. Or the reverse approach, leaving out larger areas = entire rooms. This will only shoot yourself in the foot.

A modern house is usually designed for low flow temperatures and outdoor temperature control. Thus, heating is done 24/7 or the system runs without external intervention, completely independent of the type of heating or energy source. What is important is a meticulous calculation of the system and later a professional execution. In this context, special attention must be paid to the fact that the heating circuits do not become too long and the distances are designed according to the use of the rooms. The edge zones, especially at the floor-to-ceiling windows, often require extra narrow spacing. Towards the middle of the room, the distances can then be larger.
This means: an efficient underfloor heating system has a variable spacing depending on the boundary conditions and not rigidly 10, 15, or 20 cm throughout the entire room.

The hydraulic balancing. By the way, this is always more or less mandatory for any kind of water-based heating (yes, even with radiators). However, this is the top class and here it always becomes clear whether the installer is good or not.

Different temperatures in the rooms are achieved if you understand the physics of a heating system and that of a house. The whole thing is a heated envelope and not several, even if you completely shut off one room, it will be heated by the neighboring rooms. So, in the end, you basically save nothing, because you only shift the demand. Although, for example, the rooms are considered separately for calculation purposes.

The ERR is a politically motivated matter and has its justification with radiators and other fast-acting heating types. However, with a low-temperature underfloor heating system, the ERR hardly has any effect and is as necessary as a goiter. Here I advise you to read about the "self-regulation effect." You are welcome to ask in the forum who has an ERR and whether they constantly adjust their thermostats or if they were set once and never touched again.

Furthermore, temperatures can simply be adjusted by the flow rate of the heat carrier at the hydraulic valve station = hydraulic fine balancing. In the first or even second heating period. Afterwards, there is no need to touch the system again. However, you must also consider that large jumps are not possible in a modern house (without permanently opening windows). Usually, you achieve a 2-3° difference between the rooms. With a controlled residential ventilation system anyway, because it additionally constantly exchanges and distributes the air between the rooms.

We have been living in a rental apartment with a central ventilation system for 5 years.

It is mostly due to the system itself. To save money, it is often undersized, and as a result, a pathetic 100mm disc valve sits on one or two 75mm pipes in the two-person bedroom. Before the necessary air volumes arrive, the users have long since frustratedly turned down the central unit to avoid the flow noise. Effect of the system = 0