Which smart home system is suitable for our new building?

The electrician mainly emphasized that the star wiring is the most elaborate part in the smart home and for him it is a lot of work and expensive (probably doesn’t feel like it)

Yes, it is certainly more elaborate. But nowadays I would do it in any modern building, especially if you have an inclination/urge for something like that and want to automate things in the house. Completely regardless of which system is eventually installed on top. Possibly the electrician just knows that star wiring takes longer and he always only calculates 7-14 days per job. So your construction would now throw him off track. KNX and other wired systems already start at this stage. Others, like many wireless systems, disregard this important aspect and only appear much later. This is mainly because wireless is primarily developed for the retrofit market and existing buildings.

Unfortunately, we have to use WAND access points. Ceiling mounting was not possible according to the builder (allegedly due to structural reasons). We plan to hide the WAND access point behind the TV on each floor (we don't like it visually at the top of the wall). There is always a LAN cable behind the TV anyway.

Uh-oh, that sounds like a really bad idea. APs need to be as high as possible and definitely not behind a TV that blocks the signal. Especially if you're thinking about smart home with Wi-Fi, reception is very important!

what definitely needs to be done:
-All push buttons are definitely needed (we liked the MDT glass push buttons)

At least there / for where there are no detectors. Otherwise, the bus line should be laid (have it laid) where you might need a push button later, but you can also hang them on the wall bit by bit. Buy/order push buttons rather sparingly. For example, we have only one GT II in each child’s room; it does everything including roller shutters and music control.

-All fire points are laid star-shaped in the basement and connected to the actuators

Sort of. At least lines should run from the distribution box to where you will need light later. Whether you connect a lamp there now (and thus need an actuator channel) is up to you. For example, we still have some rooms where we might get LED strips later. It's wired but nothing is connected yet.

-All presence detectors must be installed

Sort of. If you have push buttons, you can also do it gradually. Again, better to have bus lines than to need them later.

-Weather station must be installed.

Yes, you need that with every system if you have venetian blinds.

-Floor heating probably must be done too (so that the KNX push buttons can replace the ERR)

Have power and bus lines laid in the heating circuit distributor (HKV), then you can install the actuators there—or "forget" it if the heating installers and you have done a good thermal balancing.

What can be left out and retrofitted later:
-Window sensors can possibly be done later with Enocean (for us probably too late, the windows are already ordered) (The electrician appointment was unfortunately extremely delayed for us)

For me, they are one of the biggest comfort functions in the house. To check if everything is closed, ventilation function, lockout protection at the door... But if that's already over, then there is no help for it. Maybe ask the window maker again; maybe something is still possible.

-Sockets can be retrofitted later with flush-mounted KNX RF or other wireless sockets (probably don’t need many anyway) (we want to retrofit some sockets ourselves outside of the standard anyway)

I would think about where sockets should be switchable or even measurable (TV? AV-R? Dryer, washing machine, so you know when they are done? Display case with a plug for lighting?). Otherwise, see how much more the electrician charges if the rooms are wired with 5- or even 7-wire cables; then you can make multiple sockets switchable later. But I have to admit, we didn’t do that consistently either.

Did I forget anything?

I ordered 200m bus cable myself on eBay and ran it along the sockets in some rooms. It doesn’t cost much and you have the green cable in case you need one somewhere later. Buy ETS Home, take the ETS course from Eibmeier, read a lot and watch YouTube, then you can handle the setup yourself and don’t need the electrician for every *** later.

Uh oh, that sounds like a really bad idea.
APs need to be as high as possible and definitely not behind a TV that blocks the signal.

Especially if you’re thinking about SmartHome with Wi-Fi, the reception is very important!

I would like a wireless Smart Home where not every device has to be on the Wi-Fi.
For example, I would prefer EnOcean, Thread, Zigbee, or similar wireless systems.

We would prefer if the access points were hidden in the lowboard under the TV.
Our house is 150 sqm + basement (walls made of sand-lime brick), so it’s not that big and should still manage with one access point per floor, right? (even though they’re not optimally positioned)

Which access point system would you recommend?

Unifi, TP-Link Omada, Netgear, or just AVM and supply the repeaters with LAN?

Regarding KNX, I will first talk to the electrician about how expensive the budget option is with him.
Yes, the electrician will be under time pressure from the builder; he has to do many semi-detached houses relatively quickly and probably can’t afford the longer time needed for star cabling and therefore is making defensive offers.
(This is just the replacement electrician; the real electrician dropped out and didn’t take care of it.)

We would prefer if the access points were hidden in the lowboard under the TV our house 150sqm + basement (walls made of calcium silicate) is not that big and should still manage with 1 access point per floor, right? (even though they are not optimally positioned) Which access point system would you recommend? Unifi, TP-Link Omada, Netgear or just AVM and supply the repeaters with LAN?

I have many customers who hide their APs in sideboards or similarly poor positions. With an AVM 6000, for example, you can somewhat compensate for the worse position (e.g., compared to a well-installed 1200AX). But it is as far from a good solution as the sun is from Pluto. Stomping your foot and shouting "I want, I want, I want" doesn’t work here; you cannot trick physics. I expect the OP to at least acknowledge professional advice if they seek it here and not totally ignore it and therefore ask identical questions repeatedly. APs belong high up on the wall or under the ceiling; sparingly, an AVM 2400 with a LAN socket built next to it might work, but there are also less conspicuous devices (e.g., from Unifi) with POE that do not require a power outlet (which probably costs more from the electrician than the difference between the AVM 2400 and a Unifi HD).

Yes, I am looking for help with my access point here

The ceiling access points were visually not a problem for us (the builder threw a wrench in our plans, the builder does not allow the electrician to prepare ceiling access points due to structural reasons)

Unfortunately, we find the wall access points visually very unattractive and would prefer to install them hidden (even if the performance gets worse, I don’t need 1 Gbit in the WLAN)
Because of the worse position, I would want to directly choose good APs with the new WiFi 6 standard so that the poor position is compensated

The wall access points from Unifi or Omada even have an integrated switch, so you definitely have enough LAN ports

and we don’t have to spend €200 net for a simple CAT cable for each access point

TP Link or Unifi are better than AVM, right?

On the internet, the best router is often said to be the Fritzbox

What can Unifi or Omada do better than the Fritzbox? Besides the PoE operation, which is not so important for us (since the access points will be hidden)