ᐅ New semi-detached house construction – which systems to install?

Mycraft schrieb:

Unfortunately, that is still not the case.

There is a fundamental misunderstanding of thermodynamics here. All rooms within the same thermal envelope seek to reach a state of equilibrium. Therefore, rooms that are turned off are heated indirectly by the surrounding rooms. This results in an increased heat demand in the adjacent rooms, meaning energy is still consumed even if room X appears to have been disconnected from the system.

Agreement & Additional Comment: And this happens with even less efficiency, because with less heating surface, the house requires a higher supply temperature for the underfloor heating system (which is disastrous for efficiency, especially with heat pumps). Any kind of control system reduces efficiency, plus you have to cover the installation costs for the control. You can visualize this of course, but even there I don’t see any advantage, since a well-adjusted heat pump simply runs continuously, no monitoring necessary (OK, you can do it just to show off to the neighbors).

Additionally: I can imagine a useful energy recovery routine (ERR) for one case (I haven’t done it myself, since the manual effort is manageable): During the cooling period, I turn off the two underfloor heating circuits in the bathroom (the wall heating remains on), because passive cooling on tiles is uncomfortable (the rest of the house has hardwood floors, which feel very comfortable when cooled). In winter, of course, the two bathroom circuits should be open again for heating, so I have to turn them back on. I do this directly at the heating manifold.

This is all very, very helpful, thank you.

For cost reasons, it will probably be a wireless system that I can gradually expand. Besides, I probably wouldn’t use the full KNX capabilities anyway.
Now I’m wondering which system you have had the best experience with so far. Opus sounds good, Homematic (IP) as well.
Which system offers a wider range of features and also allows integration of third-party devices like Philips Hue, Xiaomi, or other brands?
And what happens in case of a server or internet outage—can I still control it in the house? At least via the physical switches?
We currently have regular outages with Unitymedia, and Alexa keeps saying it can’t reach the lights or other devices. That’s really annoying.
Sorry for all the questions, but you’ve already helped me a lot.

C.beckmann1986 schrieb:

Now I’m wondering which system you have had the best experience with so far.

That question can’t be answered directly. The systems are fundamentally different, and communication can be disrupted in various ways depending on factors like radio frequency. Additionally, support from manufacturers and many other factors come into play.

Ask five people, and you’ll get ten opinions. The size of the house and the materials used also play a significant role in wireless communication quality.

C.beckmann1986 schrieb:

For cost reasons, it will probably be a wireless system that I can expand gradually.

That often turns out to be an oversimplification because you still have to invest in conventional electrical wiring, which, in a well-planned automation setup, partly becomes obsolete. By tearing open the live wires, you may end up creating problems for yourself. But of course, everyone has their preferences.

By the way, KNX can also be expanded and scaled very easily. For example, I’m currently upgrading my lighting system to Human-Centric Lighting (HCL).

C.beckmann1986 schrieb:

Apart from the fact that I probably wouldn’t fully use the entire KNX range.

And in almost the next sentence, you contradict yourself:

C.beckmann1986 schrieb:

Which system offers a broader range and allows integration of third-party products like Philips Hue, Xiaomi, or others?

To answer your question, sooner or later, all systems will be able to integrate Hue and similar products. There are overarching software platforms like Home Assistant, Openhab, and about 500 others that can unify many systems under one roof. It’s just a question of to what extent—some features will work, others won’t.

Just use open-source software like Openhab, IOBroker, etc., for maximum flexibility. Personally, I use only Z-Wave for the actuators because I like the concept, but basically, you can mix whatever you want—that’s the great thing. It doesn’t matter if individual manufacturers go bankrupt because the devices will keep working, and if you need to replace them, you just choose a different manufacturer.

If you are in a typical single-family home neighborhood, I wouldn’t worry about frequencies or wireless interference. In my area, many use Z-Wave, and I can’t recall any situation where a wireless signal didn’t get through. In the relevant forums, you’ll also find almost no issues regarding this. I’m not sure how it is with other wireless standards, though.

Costs: Openhab, IOBroker, etc. are free (for hardware, a Raspberry Pi is usually used, and the cost is definitely under 150€ (about $160)). Additional costs are roughly 10–50€ (about $11–54) per actuator. Sensors are available across all price ranges. A friend of mine has used Shelly devices extensively—they cost practically nothing and everything runs smoothly.

You should be somewhat IT-savvy, otherwise it’s not much fun. Openhab (which I use) is relatively straightforward, but like with KNX, you need to spend some time learning. Once everything is set up, it runs without further input. There are large communities, so you can get answers very quickly to any questions, with about 99% of common questions already answered.

I have planned to use wireless actuators from eltako for blinds and lighting. They fit into deep flush-mounted boxes. The protocol is EnOcean.
I did not make the sockets switchable because I find it impractical if, for example, a socket is switched off while an external hard drive is connected.

I will gradually update things (e.g., rotary handles with tap function/EnOcean). No rush. Conventional electrical wiring is not a disaster. As long as you don’t use systems with closed source or cloud-based connectivity, it is possible to implement useful automation and comfort features over a long period.