Preparing electrical work for a smart home new construction

I can only agree with Torsan... first clarify what you actually want and don’t try to reinvent the wheel.

A PLC control system is really only advantageous for someone who knows about it and is also interested in it... for the average consumer it is nothing.

There are a variety of ready-made solutions... all have advantages and disadvantages...

I imagine the whole thing like this: at first I operate everything quite conventionally with push buttons (light, blinds, etc.) and later gradually switch to an automation solution. Therefore the idea is to lay patch cables/insulated bell wire to the push buttons and close them via 24V switching relays to use auxiliary relays for the 230V supply, to make a later switch as smooth as possible and largely without radio.

Am I so far from a possible reality with this?

With your final sentence you hit the nail on the head...

I'm getting stuck here: So in addition to closing the 24V circuit, I would need more wires to possibly be able to use KNX? How many should be planned "per switch point"?

Hm... If you pull a KNX bus cable to each switch/button, then you should be on the safe side. (I exactly missed that.... :/) A KNX bus cable has four wires. If you don't rely on KNX, you can also use them for other purposes, e.g. HM: power supply plus RS485 bus.

That’s to be expected - worse for me would be if I wanted to implement it but missed the opportunity just because I saved 500€ on extra cables during the new build...

Having it is better than needing it. However, it’s not much use if you have oversized cabling and then lose the motivation to make everything perfect in the end. I wouldn’t underestimate that.

Cheers, torsan

I always say: "You learn from mistakes, and if you are clever, you learn from the mistakes of others!"

Torsan is now at the point where you will be in a year, or when the house is finished... if you don't do it right...

Nothing against you, Torsan!

With "smart houses" there is no proper "preparation"; you either do it all or not at all... regardless of the system used... the maximum you can do is a basic installation in the desired system... but usually you have to clarify in advance where the expansion modules/sensors/actuators will go later and pre-lay the cables there.

Most of the time, this ends up being an eternal makeshift solution or it stays at the basic installation.

Please write down what you want to control and how things should be switched. What additional functions are desired and what logics you have in mind... then maybe some systems can be excluded from the start.

first clarify what you actually want and don’t try to reinvent the wheel.

That’s what I’m doing with this thread – don’t be confused by the fact that I have already thought about it (which could also be wrong). It may be that the Raspberry variant doesn’t work/is botched. PLCs have seemed somewhat suspicious to me from the start... I’m trying to explore the possibilities. Especially regarding feasibility in terms of finances.

You hit the nail on the head with the closing sentence...

In what way? Apparently, a lot of home builders have subsequently relied on automation solutions. Since I currently can’t/won’t spend the estimated 10-20,000€, I want to at least keep as many doors open as possible and not regret later that I saved a few hundred euros during the new build.

If you run a KNX bus cable to every switch/button, then you should be on the safe side

Do the cables for KNX have to meet a certain specification?
Since the buttons will be there anyway, it wouldn’t be much trouble to simply lay LAN cables or 4x2x0.8 cables there – then there would still be reserves for whatever standard. Sounds like extra costs of a few hundred euros to me, with the possibility of later going for an automation solution like Homematic wired. (currently gives me the best value for money impression) I will take a closer look at KNX soon as well.

Having is better than needing

That’s how I see it too – I would kick myself black and blue if I saved that and then realized later that I can’t implement something because I skimped on the wrong end.

However, it’s little use if you have oversized wiring and then lose the motivation to do everything properly in the end. I wouldn’t underestimate that

Of course, I don’t want to underestimate that. But the fear of not doing something is (as you can tell) much greater.

To what extent? Apparently, many homeowners have already opted for automation solutions afterwards. Since I currently cannot/will not spend the estimated 10-20,000€, I want to at least keep as many doors open as possible and not regret later that I saved a few hundred euros during the new build.

These are then just the free riders who can switch lights with their iPhone and operate the blinds/shutters... the neighbors then admire that and the builder feels like a hero... because he has a "smart home"... unfortunately, there is nothing smart about it...

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

Yes, and only the well-known green cable is approved for that... CAT cables are unsuitable.

makes the best price/performance impression on me at the moment

At first glance, yes... but you should take at least a second look....

I always say: "You learn from mistakes, and if you’re clever, you learn from other people’s mistakes!"

Torsan is now at the point where you will be in a year or when the house is finished... if you don’t do it right...

Nothing against you, Torsan!

Nonsense, I don’t take anything personally here.

I also don’t see myself at a "point of despair." : For me, everything works as desired, is done properly (professionally!) and documented.

As with many things in house construction, you realize afterward what you could have done better, prettier, or greater. You’re always wiser afterward.

My concept, which was formulated in the preliminary phase, was:
- Ceiling spots controlled by switches and E*****o dimmers (also in the electrical cabinet)
- Sockets, roller shutters, garage door, and outdoor light via HM Wired
- Glass break and opening sensors are also connected via HM Wired

There is obviously additional effort in wiring/cabling compared to the usual, of which one should be aware!

Best regards, torsan