We are planning our smart home in the single-family house

only about 30 degrees

99% of the time more like 24-26 degrees for me.

that's completely enough for warming and drying towels and light heating.

Nope, not enough. That would be just 1 or 2 degrees above room temperature.
And the surface area of a towel radiator is incredibly small.

a side question: What is it always with you people and these towel radiators? Why turn them on? Why even electrical ones?

See above.

A little update from my side: The general contractor has no problem with us completely taking out the electrical trade. The credit for this amounts to €13,500, which sounds reasonably fair to me for a fairly manageable basic electrical package.

I will now pursue two different approaches: (1) look for a local electrician with KNX experience who takes care of everything from planning to installation and commissioning (2) look for a remote KNX/Smart Home expert who handles planning and the control cabinet as well as a local electrician for "simple" execution work regarding wiring and connection

If there are any tips or experiences related to this, they are of course welcome. There seem to be online offers for smart home planning + hardware and programming for €15-25k. If I now find an affordable local electrician for around €10k (?) I end up with maybe around €35k in total? That sounds quite attractive to me at first.

(2) Music in the bathroom: This is mainly about the guest toilet. At least as a guest, I am happy if not every fart and every trickle is audible to people in the .

You prefer to do your business with elevator music rather than supply the many spies in the hallway with information? On the other hand, even the health insurance covers the specialist.

The 'eating' scene is activated at the switch in the common room (we have this scene on several buttons, for example), kitchen lights dim, dining table lights turn on, Sonos speakers turn on, and the LED upstairs shows Aurora. Upstairs, the scene can be turned off again from two switches in the children's room (bed and door), in case the child does not want to come to eat.

And during the holidays at grandma's, children experience security for the first time, crazily retro fully analog being called to eat? Seriously crazy.

Go to the KNX user forum and look for a system integrator there.

Maybe as a point of reference for you:

For our single-family house, relatively large, no fancy LED gimmicks but a few special features (pool control, in addition to the front door also side doors + courtyard gate etc.) we agreed on 15k EUR with the system integrator, which includes complete lighting and electrical planning, a "shopping list" for the hardware, supervision of the electrical installation, and the configuration of the whole system. We currently estimate hardware costs at about 15-20k, although knowing myself a bit more will probably be added.
Electrical work is extra; we are waiting for the offer, it will probably be somewhere around 30-40k.

Go to the KNX user forum and look for a system integrator there. Maybe a reference point for you: For our single-family house, relatively large, no fancy LED gimmicks but a few special features (pool control, in addition to the front door also side doors + courtyard gate, etc.) we agreed on €15k with the system integrator, which includes complete lighting and electrical planning, a "shopping list" for the hardware, monitoring of the electrical installation, and the parameterization of the entire system. We currently estimate hardware costs around €15-20k, although knowing myself, something will probably be added. Electrical work is extra; we are waiting for the offer, it will presumably be somewhere between €30-40k.

Wow, then all-in you are at €60-75k after all. That would be way too much for me. I currently find it very hard to estimate the costs but hoped that one could get below €40k all-in if handled cleverly and without sacrificing functions. Let’s see if I am wiser after the first consultation talks. I have now found 7 providers nationwide with corresponding offers. I will check them out and see what comes of it.

When I think about it, 80t is certainly more realistic for us than 60t. But as I said, bigger, more comprehensive, can definitely be solved more efficiently.

But - based on everything I've read so far, and that's quite a bit, I consider under 40t almost impossible, unless you only commission one system integrator for planning and then implement everything yourself (maybe 10t planning, 10-15t hardware?)

However, you save a bit elsewhere for that, although it's rather difficult to quantify. For example, control of shading, ERR, awning control, and such things are then omitted from other trades because they are already integrated/considered in KNX.