Which smart home system is suitable for our new building?

POE switches naturally need more power the more devices they have to supply power to themselves. ;)

But in total not more than if you power the individual devices independently

Total poe switch and total normal switch and all individual devices e.g. access points

In total it should be similar, right?

I would assume so now, yes. I would even claim that the PoE switch is more efficient than operating all devices with their own power supplies. The switch only has to convert from 230V to 24V once. Without PoE, each power supply has to convert from 230V to 24V separately. But that is just a claim. It would have to be measured, but I could imagine that the PoE switch consumes slightly less overall in the end.

The technical data for all devices is freely available. You just have to compare.

If both have similar power consumption, I would take the better system

What would you recommend?
1x 12-port poe switch or 1x 8-port normal switch and 1x 5-port poe?

Does it make more sense to have only 1 switch or to keep the poe as small as possible?

No matter what you take, for your 12 LAN sockets you have one port too few on the switch because you forgot the uplink.

Have you already chosen the exact POE devices? Without this selection, choosing a switch is not possible because the POE standard and the POE budget must be considered.