How to smartly wire door/window contacts/buttons/LEDs? HA vs Dali-2 vs KNX etc.

I have to finalize my electrical planning for a new building within the next 2 days. The conditions are:
(I don’t need a moral lecture about why I’m only starting completely right before submission (there are reasons), but rather I need very targeted tips.

- The builder does not allow any fundamental changes to the power/light wiring/switches etc., so, for example, making every socket switchable via KNX is out.
- However, I have the option to have additional cables (any kind, including KNX bus cables, additional 5x1.5 cables, or pull cables) and also empty conduits installed at any locations as empty boxes or wall outlets.
- Basically, I want to use Home Assistant with a NUC/MiniPC in the basement as the “brain” (I’m really excited about programming and using various components, with many already available), and everywhere in the house to control any functions via retrofitted push buttons, and of course also via voice.
- Which push buttons (Zigbee, Aqara) or something from DALI etc. is still open.
- I want to mainly use LED strips for lighting in the house on ceiling edges, in dropped ceilings, and in baseboards, especially in the living room/kitchen.
- I want to exclude Loxone since it is too closed/off.
- LAN/WLAN, access points & possibly cameras (PoE) all from UniFi.
- Most sockets do not need to be smart; only a few as needed via Shellys/Sonoff or directly via smart LEDs/Zigbee.

After days of research I still can’t get further in the endless possibilities: My idea to be flexible:

All questions somehow belong together, better to read completely first!
I want to avoid having DALI & KNX bus cables (just in case) installed simultaneously (double costs).

a) Main question: How/with what do I read door and window contacts, glass break sensors? Here I would prefer a wired solution.
1) Via Home Assistant / ESPHome -> Konnected Alarm Panel -> many binary inputs, with reed contacts/sensor lines running directly to the basement?
2) Via DALI-2 bus? DALI-2 is supposed to support binary devices, Part 306 is said to support all universal sensors – but I can’t find anything more, are those still classic reed contacts that I read into binary inputs in the main distribution (Helvar Imagine 910 DALI Server or Lutron Vive DALI system)? Or are those special sensors that I can directly connect to the DALI-BUS (2 BUS conductors 1.5mm²) star-shaped/arbitrary (except ring)? Or can you put reed contacts directly on the DALI bus? I also read that there are DALI motion detectors with a free binary input (although one would be too few), or are there special binary inputs where I can collect room-wise reed signals that are then translated onto the bus?
I could have an additional DALI-BUS line/box (5x1.5mm², two of them for the bus) laid in every room to/over the main light switch, and from there go further to all needed sensors/actuators (DALI lamps/LED controllers, roller shutter actuators, window contacts), so I would not have to run every single sensor to the basement/distribution. – WHAT is the best, smartest solution here? For every light switch (which then becomes a push button, LED on permanent power, switched via DALI bus) I would also run 5x1.5 instead of 3x1.5.
3) All questions from 2), but via KNX bus? Only if it absolutely does not work with DALI-2? It would be nice if I had the option to use DALI, it is also easier not to have to lay additional KNX bus cables directly to the lamps. Besides HomeAssistant NUC and DALI server, I would rather not run a third KNX server.

b) Would DALI/KNX even be the best choice for my project with limited possibilities, or should I simply have all cables (where sensors are going) laid into the basement and decide later how I read them? – Or then rather KNX bus cable instead of DALI bus cable?

c) Could I also, if DALI bus is installed, use DALI/Gira push buttons instead of ZigBee push buttons, and use/program/control them just as well in HomeAssistant?

d) Does DALI even make sense for lighting if I want to use lamps from many different manufacturers anyway? I really like the Paulmann MaxLED, good price/performance ratio. Barthelme LEDs are supposed to be very good too (but then again only with DALI/KNX/BT).

Thank you very much, any tip helps me!

My gut response: Don't do it!

Because:

1.

I have to finalize my electrical planning for a new building within the next 2 days

You cannot complete a planning from scratch for a bus wiring in 2 days, no matter which system.

2.

The developer does not allow fundamental changes to the power/lighting wiring/switches etc., so for example making every socket switchable via is out.

This is the deal breaker. Because a bus wiring is not simply classic wiring plus some bus cables, but the whole setup is completely different.

I am not familiar with DALI, so only regarding KNX.

Example 1:
Of course, you can lay all window contacts into the distribution box and connect them to a binary input there. But what do you do with that information? Usually, you want to control something with it, e.g. the blinds. But that only works if the blinds are also connected to a KNX actuator, meaning they are also centrally located in the distribution box. Unless you lay a bus cable to each individual blind and install a flush-mounted actuator plus visible wall box at each blind, because the actuator must be accessible for maintenance. Then you could also take a flush-mounted blind actuator with binary input and lay both connections there. But that is expensive and hacky.

Example 2:
For lighting, you don’t need an extra bus cable, but a switching actuator. That is why the power cable for the fixture does not go to the wall switch but to the distribution box. If they force you to install a classic wall switch, the only way would be to lay an additional bus cable there and install a flush-mounted actuator in the switch box. Possible, but expensive and hacky. And often you still want to have a wall switch, for which a new box in the wall would have to be installed because the existing one is built up.

And this continues with everything else. Switchable sockets or power measurements are almost impossible without tearing out every box from the wall again after the electrician is done, creating new work space in the wall, and rewiring. That won’t work. And certainly not in 2 days. The probability that you forget or ignore something is exactly 100%.

I planned my entire house electrical system alone and invested about 6 months for it (including familiarization with KNX and ETS). Just for comparison.

My gut response: Don't do it! ... That is the knockout criterion. Because a bus wiring is not simply the classic plus a few bus cables, but the entire setup is completely different.

Thank you very much for your detailed answer first of all!
So my planning is only preliminary anyway, afterwards I would still have 6 months for the detailed planning, and only then is the handover/completion of the house.
-
Basically, I don't want to switch sockets at all (that doesn't work for me anyway, since the sockets are not routed individually to the basement, understood).
But assuming: I run a KNX bus cable from the basement, where the main KNX unit is located, to each room (flush-mounted socket below/next to the normal switch), and sometime later, as soon as I have access to the house, I install a KNX switch connected to the bus at the flush-mounted socket, and then I lay additional bus cable by myself from this flush-mounted socket to the shutter flush-mounted socket where the actuator is located (and via the actuator I then read via the binary input (if normal reed contact) or I go directly on the bus with a KNX window contact, then all participants/switches/sensors/actuators are on the bus (can communicate with each other decentralized and are connected to the main bus), isn't that enough? Or is this exactly the problem?
Can the KNX shutter actuator be powered from the already existing 230 V of the shutter motor or does this KNX shutter actuator have to be necessarily separately "powered/controlled" from the main distribution/main KNX unit in the basement? If yes, that would indeed be a problem. A Shelly, for example, is powered directly by the existing 230 V, just connected in between. The solution here would be: for the shutter actuator take a Shelly, and Home Assistant gets the values directly from KNX and can then simply control the Shelly actuator accordingly.
If this wiring effort (room by room, with interruptions for programming etc) is OK for me, is the project from your point of view still a mess? From my point of view, I have to lay cables to each individual sensor anyway, if all sensors go on the bus that has the advantage that I do NOT have to run to the basement with every sensor, but everything hangs in series (not in a loop) on the bus?
I don't understand the connection at this point.
If you give a concrete answer here again, it would help me a lot!

and regarding 2): Aren't there small KNX flush-mounted actuators for behind the socket that are connected between the normal 230 V voltage, connected to the KNX bus to switch this actuator? Like a Shelly, just wired instead of wireless?

and to 2): are there no small KNX flush-mounted switching actuators for behind the socket that you connect between the normal 230V voltage, connected to the KNX bus, to control this actuator? Like a Shelly, but wired instead of wireless?

I completely agree with .

You have not understood the logic and necessary wiring of KNX, to say nothing of the required interfaces, for example between KNX / HA / .....
It does not work "just like that," it should be properly planned on one system beforehand and then you can look at which integrations are necessary, but you should not just start blindly with such an important topic.

But suppose: I have a KNX bus cable laid from the basement, where the KNX main unit is located, to every room (flush-mounted box under/next to the normal switch), and sometime later, as soon as I have access to the house, I install a KNX switch connected to the bus at the flush-mounted box, and then I lay additional bus cable myself from this flush-mounted box to the roller shutter flush-mounted box where the actuator is located.

So you want to break open the walls again right after taking over the house? How do you imagine that, if the switch and the roller shutter are not on the same wall?

Isn't that enough? Or is that exactly the problem?

Theoretically, that works. Have you looked at how much flush-mounted actuators cost? You need one for each light and each roller shutter. And so far you only have lights and roller shutters.

Can the KNX roller shutter actuator be powered from the already existing 230V of the roller shutter motor, or does this KNX roller shutter actuator necessarily have to be separately "powered/controlled" from the main distributor/KNX main unit in the basement?

Both, 230V and bus cable. You keep talking about the "main unit," but there is no such thing in KNX. There is only one power supply per line. But that has nothing to do with a central unit and could theoretically be located anywhere. Also, KNX wiring is not done star-shaped from the distributor but in a tree structure. As I said, you lack fundamental knowledge, which cannot be acquired in two days.

If for me this wiring effort (room by room, with interruptions for programming, etc.) is OK, is the project still a mess in your opinion? From my point of view, I have to lay cables to each individual sensor anyway; if all sensors go to the bus, the advantage is that I do NOT have to run to the basement with every sensor, but everything is connected in series (no loop) on the bus? I don’t understand the connection here.

Yes, it would work that way. And it’s still a mess. In the end, you have a flush-mounted box with a blind cover on the walls for every actuator and each originally installed conventional switch. How does that look? You pull the cables into the basement because there you can wire all windows to 1-2 binary inputs, all roller shutters of the house to 1-2 roller shutter actuators, and all lights to 2-3 switching actuators. The cables in the walls are plastered over and gone because you never have to access them again. A normal actuator or input with 8–16 connections costs roughly twice as much as a flush-mounted actuator. That means you generate eight times the cost just from that.