Best retrofit smart home new build

It's simply in the nature of the thing. Swallowed telegrams and long response times are the order of the day here.

hmm PoE and powerline Ethernet are actually quite successful standards. So I wouldn't say it's in the nature of the thing. Do you have a lot of negative experience with Digitalstrom?

ok then Digitalstrom is unfortunately also out.

I have now spent a long time dealing with the topic of smart homes and the conclusion is that only the following solutions remain:

Retrofit: basically only works via radio, right?
New build: via cable if the electrician or builder cooperates.

If the new electrician cooperates in the smart home area, I still have questions about cable smart homes.

What is the difference between a bus smart home (KNX) and a smart home wired in a star topology?

Apples and oranges. It works accordingly where the systems were developed for. Of course, not always without restrictions and always only as good as the quality of the transmission medium and the components used allow, and that’s exactly where the crux lies.

There are always occasional opportunists who bet on PL, but that remains just a niche product or disappears just as quickly as it appeared.

With PoE, the whole thing is basically completely separated from each other and without influence of alternating current, so basically something totally different, since separate pairs of wires are used for transmission in the consumer sector.

With Digitalstrom, the matter is as I described it. It is for someone who does not care much about fast response, variety of options, and again good value for money. Reliability, yes, is also somewhat lacking.

But still wants a bit of this smart home from the TV without major remodeling or even exchanging light switches and lamps.

Price-wise, as I said, it is also positioned above KNX.

And yes, my negative experiences with Digitalstrom are the response times and the price. Both are simply not satisfactory.


Yes, retrofitting is rather only suitable for wireless. For everything else, you simply spend more money than necessary. Because clever planning, component selection, installation, and integration are the keys with cables.

What is the difference between a bus smart home (KNX) and a smart home that is wired in a star topology?

There is none. It’s the same thing just in green.

how can KNX be installed as cheaply as possible?

where are there savings potential in KNX?

Where is there potential for savings with KNX?

Do a lot yourself. In particular, programming or parameterization is expensive because with a good SI or good electrician you are buying years of experience.

What is the difference between a bus smart home (KNX) and a smart home that is wired in a star topology?

I think he means the difference between bus/SPS derivatives. With the bus you can connect everything anywhere and distribute the line flexibly (almost, no ring!) as you like. With the star (if it is necessary, like e.g. with the simple Loxone) everything must be wired individually into the distribution board. Of course, this is more complex. In short: bus (e.g. KNX, DALI, SMI, etc.) saves effort in wiring and is much more flexible. Although you can also lay a bus system in a star topology, that would be nonsense.

How can KNX be installed as cheaply as possible?

Use KNX-RF, that saves a lot of cables and their installation. But is that what you want?