Best retrofit smart home new build

I do not have exact details about the electrical system yet

but I strongly assume that the cheapest option is always installed as standard

Roller shutter motors (dumb ones that only operate with a push button)

I have not yet decided on a manufacturer

Which manufacturers can you recommend to me in the area of Z-Wave?

As a central control unit that could connect everything, I have found Homee, but you are welcome to suggest better alternatives

I look forward to further suggestions that I do not know yet

of course Somfy also has "dumb" motors that can be controlled with any actuator.

Of course, that's why it says it's an example... Somfy is used because everyone knows it... But no one yet knows if and which motors will be used. I know of GÜs who install radio motors by the dozen because they are cheaper in the overall construction, as you save the extra hours for the electrician. But the resident then loses out because they end up stuck in the vendor lock-in trap.

I don’t have exact details about the electrical system yet

Yes, that's the crux of the matter.

The cheapest standard is different with every BT.

But yes, I would look around at z-Z-Wave, it most likely has the greatest potential.

I have not yet settled on a manufacturer

That's a good thing!

Which manufacturers can you recommend to me in the Z-Wave area?

None at all! Because that is exactly the wrong approach. To commit to one manufacturer. That contradicts everything that the term smart home originally stands for and means.

Sure, nowadays it is so overused by marketing and advertising that most people think something like colorful lights and plug-in adapters in the sockets and possibly thermostats with internet access... and the smart home is ready.

as a superior control unit that could connect everything I found Homee but feel free to suggest better alternatives

You will have to rely on several hubs from several manufacturers, one way or another.

ok I will first try to find out which wireless standards I want to use possibly even combine several

Enocean is used when there is no power connection

what is the difference between Zigbee and Z-Wave?

what about KNX-RF that's the KNX wireless standard should one possibly go for that?

Wlan is basically out

what is the difference between Zigbee and Z-Wave?

They are two different wireless standards, one rather proprietary and the other open. There are also constant changes; precise specifications can be found with the respective alliances. KNX-RF is to be understood as a supplement. Building an entire house with it will be difficult. The wiring also has to be suitable. You won't get very far with conventional wiring as you usually get it.

I can only keep recommending OPUS here...