Preparing electrical work for a smart home new construction

Do the cables for KNX have to meet a specific specification?

I think the best thing is if you:

[*]Define your requirements
[*]Look for an experienced electrician
and work out a solution with them

Cheers, torsan

Please write down what you want to control and how things should be switched. What additional functions are desired and which logics you have in mind... then you might be able to exclude systems from the start.

Ok, for the moment my requirements would be: - Control roller shutters (time-controlled, via manual switch or reacting to an event) - Control lights/outlets (indoor/outdoor) (time-controlled, via manual switch or reacting to an event) - possibly also query/control heating thermostats (time-controlled, via manual switch or via sensors) in general: query sensors (windows/doors open/closed, possibly also vibration and motion, or also room temperature, humidity) and if necessary start events (send notifications/execute one or more actions) As a nice-to-have, control via tablet would be great. (I could put together an HTML/Python program via FHEM.)

but usually one has to clarify in advance where later the extension modules/sensors/actuators will be placed and lay the cables there in advance.

My idea would be that the complete "control of the components" disappears into the control cabinet and "only" the admittedly elaborate wiring to the motor/sensor is installed. (For example, roller shutters and window contact switches would have to be wired in advance.) The sensor lines for temperature/humidity/motion could be laid at the place where the light switch for the room is installed and used later (with a corresponding cover from the switch program). The line for the window (whether closing contact or intrusion detector) would then already be laid up to the window. Windows with contact switches could possibly be ordered directly in advance to avoid tinkering later on at that spot. This way the lines to the control cabinet would already be in place. That's it for now, as far as my thoughts have wandered so far.

At first glance yes... but you should look at it at least twice....

I'm currently working on that and am naturally still relatively at the beginning. The idea for a (at least somewhat) smart home is still quite young and came out of a Raspberry DIY project.

Hmm, so relatively simple basic functions...

So many options come into question, ranging from Homematic to Loxone, free@Home, various standalone solutions up to KNX.

The question now is how far you want to take it and whether a closed or proprietary system is sufficient... the visualization you are talking about could then run on the Raspberry...

Yes, I also think that I (so far) don’t have anything extraordinary planned with it.

However, when I look at the costs, it is relatively certain that I will not have the installation done during the new construction. As I see it, for example, a basic Homematic installation for about 10 roller shutters and window contacts alone would cost over €2000 without labor. I also found the free@Home concept interesting, where the bus consists of only 2 wires, which I would already provide with a star-shaped electrical installation via pushbuttons anyway.

At the moment, I can most easily warm up to the idea as it is currently planned: star-shaped wiring to the distribution board and additional wires to the "measurement points" to implement one of these solutions later. Whether it will then be the certified KNX cables would still be an option. (But I have not progressed very far in KNX research yet)

I will get in touch with the sales partners in the coming year (not long now) to see if and how something like this can be implemented. It doesn’t seem far from possible.

In any case, I already thank you for your suggestions and tips and am, of course, open to further input!

The free@Home is only a stripped-down version of the KNX bus, which is very limited in the number and possibilities of devices...

KNX is also just a TP bus...the second pair is only used as a reserve or for powering power-hungry components...but usually the second pair is not used at all in a single-family house due to lack of necessity.

Ok, now the consideration for me remains to lay the certified cables right away, to be secured for the near future at first. The star-shaped wiring will definitely be installed and everything initially connected conventionally via [Stromstoßrelais].

When I then see that I have to plan about €80 per shutter actuator for Homematic – in addition to the other equipment, that will definitely be an investment for a building society saver or other spontaneous financial injections.

In any case, many thanks already!

... and a Happy New Year!