Smarthome - I don’t need one ... or do I?

Yes, and that's exactly where the problem lies. With "normal electrical installation," you have virtually nothing. If it is supposed to be a structured cabling for a future-proof smart home.

For that reason, you have to sit down beforehand. Develop a concept. Create a room book. A wiring plan. A switch cabinet plan. A specification sheet. Etc. pp.

And then you will realize that there is hardly anything to do with "normal electrical installation." Which necessarily means that this item will be relatively low. But then there is a large chunk of structured cabling. Which, however, does not represent an extra charge but replaces the usual electrical installation.

That means, as I wrote at the beginning: not 20K + conventional but 20K instead of conventional. Yes, of course with a variable +Y. Because appetite comes with eating, and most people want even more once they find out what is actually possible.

But yes, I also understand what you mean. You want to do the flush-mounted installation yourself. Only it is the case that you can do a conventional wiring almost on the fly... walk through the rooms with the electrician and draw a few lines and circles on the walls. For structured cabling, more preparation is definitely needed. Certainly fewer sockets have to be installed and sub-distributions belong to the past in a "normal" single-family house. But more cables are laid, 230V and SELV, and it is to be expected that the switch cabinet size will be a factor of 2-3 (sometimes even 5).

already wrote: IT specialists are biased. But why always established systems like KNX and Loxone are chosen instead of a fine OpenSource system (OpenHAB ...) for comparison of conventional electrics and SmartHome is beyond my knowledge.
The wiring of all SmartHome systems is similar, a bus system requires somewhat fewer cables than a pure star-shaped wiring which we have. But never mind. After 4 months in a largely self-built and electrified and somewhat smartened house I can only say: OpenHAB runs great. Slowly a few more gimmicks are added (various sensors with the option of long-term recordings, smaller programming like slat rotations of the blinds to e.g. 90° as desired. Naturally after position determination of the blinds (time measurement at top and bottom ;-) and many other things. Especially as an IT specialist I recommend: do it yourself. Wiring is easy, programming initially moderately difficult, afterwards always easier. Above all you know how what works and don’t have to call a system integrator if you want to add, change or replace something. Of course bus buttons (KNX/Loxone components) can also be integrated, but it’s not a must. I just wanted to throw it in as an option in the discussion, not to unleash a religious war :p

I am 110% with you on that. Everyone complains about the exorbitant prices for KNX and the like instead of just looking around once.
There are plenty of cheaper alternatives which in my opinion are also significantly more flexible.

For years we have been running IOBroker on a Raspberry. We have a star-shaped wiring, simple EIB cable leads to completely normal Gira 55 light switches or push buttons (no complaints from the girlfriend ;-) ) which in turn directly switch the relays for light/shutters. These relays send and receive signals via MQTT to and from the IOBroker (or Openhab). If the server is unplugged because someone needs the socket from the Raspberry for the vacuum cleaner, for example, the light can still be switched on and off. So the basics definitely run even without the server.

Additional push buttons (or the second push button) are reported to the IOBroker via Modbus Digital Input Converter. These are then the lights that do not necessarily have to be switched via exactly that push button, for example switching off the kitchen light from the living room push button.

One lamp shows me color-coded whether and if yes, which garbage bin I have to put outside. The data is stored in the Google Calendar and the cost for this is a Zigbee LED bulb (no idea what it cost me once. €15?) and a Zigbee dongle (from €9?). I had to check whether this would also work with KNX. When I saw that the plugin for the Google Calendar alone is supposed to cost €80, I didn’t look any further.

Programming is really, as i_b_n_a_n already said, with the known OpenSource systems after a short time child’s play and one is very flexible about what, when and where should be switched and, as i_b_n_a_n also already wrote, one can do it oneself and doesn’t need a system integrator.

Best regards

Hannes

PS: Just as an example. The Modbus DI module with 32 inputs for light switches/push buttons costs ~€22. You need the light switches anyway and the EIB cable is cheaper than NYM cable

If "Smarthome," then my decision would be: do it right from the start. As Mycraft already wrote, there is little left of normal electrical installation.
"Do it right" also means for me to rely on an established standard (KNX) and not get stuck in a manufacturer's system or use a homemade DIY solution.

With Loxone, Free@Home, and all the others, you are more or less at the mercy of the manufacturer. If they discontinue devices or the entire system, support becomes difficult.

"DIY solutions" certainly work well but can only be maintained by the builder. After all, the house might one day be sold. Or the builder might be in hospital for a long time (or worse). Then the rest of the family can do little in case of errors. Such DIY solutions often also reduce the value of a property when selling.

Apart from that, a KNX-based system can also be expanded very well with tools like ioBroker or OpenHAB. However, I would always represent the basic functionality via standard KNX.

He wants to switch a few sockets, monitor the mailbox, and control the light. For the price of the KNX installation, he can also hire someone to occasionally check if the mail has arrived ;)

I would not exactly consider systems like Modbus as a "DIY solution", after all it is the most widely used industrial standard worldwide in this area and the devices are correspondingly mature and affordable. This standard has existed since 1978 (KNX was . You can usually retrieve data from photovoltaic systems, charging stations, etc. via a Modbus interface. Of course, you can install an (expensive) KNX interface to access the data.

For the three things the original poster would like, I would use a Siemens Logo 8 with a Modbus interface. Price-wise it is reasonable and the future-proofing should also be given.
- The control of light and sockets is handled by the Logo. Also the actual control
- the connection of the heat pump and photovoltaics, possibly in a few years the car charging station via Modbus
- underfloor heating and presence either Logo or Modbus

Personally, I would distribute a few inexpensive temperature and humidity sensors (Modbus or Siemens Logo) inside and around the house and install electrically operated roller shutters as an absolute "must have", which keep the heat out in summer, controlled by a brightness sensor and the temperature sensors. Of course, you can also combine this with the presence detector so you are not sitting in the dark.

On top of that, you can then run Openhab, IOBroker, or similar, and because you saved the money on the expensive KNX components, you can do all the nice little things that are possible nowadays and as most of us have already noticed, there are countless such little things and you always come up with new ones :)

...
"Doing it right" also means to me to rely on an established standard (KNX) and not to be trapped in the system of a manufacturer or to use a homemade DIY solution.

With Loxone, Free@Home, and whatever else they are called, you are more or less at the mercy of the manufacturer. If they discontinue devices or the entire system, support becomes difficult.

"DIY solutions" certainly work well, but can only be maintained by the builder. After all, the house might also be sold someday. Or the builder might be in hospital for a long time (or worse). Then the rest of the family can do little in case of errors. Such DIY solutions often also lower the value of a property when selling.

Apart from that, a KNX-based system can also be very well expanded with tools like ioBroker or OpenHAB. However, I would always map the basic functionality via standard KNX.

We have "Controllinos" and "Smartmanager", both not DIY solutions but industrially implemented Arduinos or Raspberry Pis. If you look closely at what the Raspberry Pi controls (in industry), no one doubts anymore that the Raspberry Pi can also control a single-family house (and is actually bored the whole time ;-)). A suitable documentation together with proper labeling of the hardware is maintained by us for everything so that "knowledgeable third parties" can continue, adapt or change the system at any time. If necessary, Controllinos can be removed and relays (industrial relays ;-) ) can be controlled directly as described by . Controllino "firmware" is separately secured on a server for each residential unit so that replacements can be quickly made... The Raspberry Pi with OpenHAB and ioBroker is programmed "universally" with many variables so that it can be used in all 4 residential units (one is kept as a spare) and only the IP address needs to be adjusted. So a matter of a few minutes. By the way, we are currently considering moving the logic of the Raspberry Pi (OpenHAB and ioBroker) into the cloud (in the future "fog"). For example, 1-wire temperature sensors cost 1.xx € (I believe 5 pieces for 6€). 1-wire humidity + temperature sensor combos something around 6€ net. Wiring directly to the Controllinos (like all standard Gira 55 switches), logic with long-term logging is done by the Raspberry Pi. (soon with backup to the cloud)

If it's "smarthome," then my decision would be: do it right from the start. As Mycraft already wrote, there is little left of normal electrical installation. "Doing it right" for me also means relying on an established standard (KNX) and not being trapped in a manufacturer's system or using a DIY makeshift solution.

With Loxone, Free@Home and whatever else they are called, you are more or less at the mercy of the manufacturer. If they discontinue devices or the entire system, support becomes difficult.

"DIY solutions" certainly work well but can only be maintained by the creator. The house might even be sold someday. Or the creator could be in the hospital for a long time (or worse). Then the rest of the family can do little if errors occur. Such makeshift solutions often also reduce the value of a property when selling.

Apart from that, a KNX-based system can also be easily expanded with tools like ioBroker or OpenHAB. However, I would always map the basic functionality via standard KNX.

The selling price of a house is certainly not reduced by an installed openHAB solution. The wiring allows switching to KNX or similar at any time. The important thing is the existing infrastructure (star or bus wiring). It is more likely that selling will be difficult if there is no fast internet available or if the wiring is "conventional." Although selling will probably be difficult these days even for junk properties :p