Smarthome - Which system for new construction?

I wouldn't even need an astro timer switch. No remote control, nor anything automatic linked to conditions via smartphone or anything else. I just want to save the time of manually pulling all the blinds up and down every day. Ideally, a switch in the hallway with 2-3 groups per floor that I press and the group goes up/down or down 3/4. It's not as automatic/"smart" as based on weekdays or even the position of the sun, but still much faster than doing everything manually. And if I know in the morning that I'm leaving the house and it's going to be scorching hot today, then I'll just lower the blinds on the south side down 3/4 or so accordingly.

Set up KNX for that? I mean, KNX itself already costs a license and so on. There must be simpler solutions?

I already wrote it, for your task separation relays are sufficient. But regarding future possibilities and new needs that may arise later, which are not yet present, it could possibly be a dead end.

KNX costs the end user no licensing fees. You are on the wrong track there.

Otherwise, just choose a radio system and cover everything with it as far as possible.

KNX - MDT JAL actuator + MDT weather station

Do you only use the built-in logic or with an additional logic server etc.? I have installed the same components, but have not yet activated the automatic shading. What I would like is shading depending on the outside or inside temperature. For that, I will surely need a logic engine or something similar.

Use simple offline solutions with "dumb" isolating relays and actuators. That covers your requirements. If you want to "play": KNX. When making decisions about the house, I always focus on ease of use for all age groups and less tech-savvy people in the household, and on minimizing the number of online data collectors running in the background while I simply "live".

that I serve as few online data collectors in the background as possible while I am simply "living".

Very important point in my opinion as well. That is why all solutions for smartphones etc. should be treated with caution (does not mean that it can’t run cleanly there either).

Thank you Mycraft, then I will probably tell the electrician that I would go in the direction of a relay.

Therefore, all solutions for smartphones, etc. should be approached with caution (which does not mean that it cannot run smoothly there).

For this reason, I avoid many of the so-called smart home products like the plague. Most of what is called that nowadays diligently collects data about the residents and their behavior and bypasses the security mechanisms. Since everything is supposed to be controllable via its own app. Very few people know how to effectively prevent this and just let everything run. Data breaches have meanwhile become a daily occurrence.