Which router for our new building?

Take LAN double sockets. Extra cost with us about 20% compared to single sockets

Maybe the socket, but the cables should also be double.

I have never heard of unify until now.

Harmonize your Enterprise, they used to be Siemens.

The socket maybe, but the cables should really be double as well. Harmonize your Enterprise, they used to be called Siemens.

Eh, please? Unifi, not Unify :) And they never had anything to do with Siemens. Ubiquiti (the company behind the Unifi system) was founded in the USA. I also have some devices from them (switches, APs, cameras). I find the whole system brilliant and absolutely reasonably priced.

Eh, please? Unifi, not Unify :) And they never had anything to do with Siemens. Ubiquiti (the company behind the Unifi system) was founded in the USA.

Oh, which of the two companies’ trademark lawyers might have been sleeping when a competitor has such a similar name? – I’ve already wondered what Unify should be doing in the consumer segment. Just imagine if another car manufacturer called itself Aodi or Furd, a soda Pebsi, or an adhesive tape Teza ...

Do I need to consider anything else for my network?

Besides enough LAN ports
and the PoE preparation for the APs?

Which video doorbell would you recommend to me?
Should it also support PoE?
What else needs to be prepared for a video doorbell?
The standard is a normal doorbell system

The video doorbell should ring normally inside and possibly allow adding another chime in the attic, and send the video signal to the phone or smart display (e.g. the Echo or from Google)

and the POE preparation for the APs?

You don't need any POE preparation for the wiring, whether for the regular network connections or the ones for the APs. Later, for operating the POE device, you simply need a POE injector or POE switch.

What I would clarify is how the cables for the access points come out of the ceiling (or if necessary, out of the wall). Ideally, use a deep box and equip the installation cable only with a keystone module. Connect a short patch cable from the keystone module to the access point. Put all the cables into the box and mount the access point under the box.

In general, you should ensure that network cables are laid in a way that they can be exchanged inside the conduit. This is elaborate and the electricians don't like it at all. You should also discuss this with the electrician in advance.

I can't contribute anything about the video doorbell. It is recommended to lay an empty conduit and then install an appropriate cable depending on the system. (Nothing is more future-proof than a sufficiently thick empty conduit!) For a video doorbell, pay attention to the height. If it is installed at standard height, usually you won’t get a good image.

What I would clarify is how the cables for the access point come out of the ceiling (or if necessary from the wall).

Correct! NEVER let installation cables just come out of the concrete, always with a box. Otherwise, it won’t work.