Cat6 to the light switches from the main switch board / sonoff

Hi guys,

I am about to start building a house and designing the whole home automation system now.
Thinking of putting CAT6 with a push buttons to every light switch in the house.

In the main switchboard, I need some relays which can be controlled by those push buttons and from home assistant via network or wifi.
I can put Sonoff basic switch and connect one pair from CAT6 to trigger the light switch, but I will end up with about 20 Sonoff basic modules, which is not ideal. Maybe I can put Sonoff 4CH, but as far as I understand - I cannot connect and control all 4 channels with the external button, tell me if I am wrong, please.

Are there any other devices which can do that? Basically, the requirement is to have a relay in the main board, which can be controlled by external button on the wall and from the home assistant.

Thanks.

Youtube this guy superHouse TV

Hes done some good stuff

This was going to be my suggestion. He also sells some of the products he made/uses in getting his setup going.

The ability for him to change what a wall switch of button does without re-wiring is very cool. Just change it in the software side of things.

Basically superhouse inspired me for that project. Seems to be clear with the switches, they are just connected to Arduino, which sends command to mqtt broker, which is Home Assistant in my case. But what is next?

In superhouse the next step is another Arduino, which receives commands from home assistant to controlls relays. What are those relays? Not very clear from the video

The relays are just DIN mount relays. Be careful that you don’t over-design the new home. When you move in a few years, maybe a lot of years, you can’t expect the potential buyer to fall in love with your smart home. And if your design is so custom that only you can maintain it, the buyer won’t see any value in it at all.

I am fairly new to home automation. (Well, I did have a house full of X-10 many years ago). But I do have considerable experience with electrical wiring. Here’s some thoughts: Your building codes may require conventional wiring- that is, line voltage and conventional switches in every box. Your electrical installer should be able to guide you before the town inspector says, “pull it out”. You can not mix high-and low-voltage wiring into one box. (Carlton makes a plastic divider to separate HV and LV in a dual-gang box). That means you can’t run CAT6 wires into a box that also has 110V line voltage. Also, specify non-metallic boxes, otherwise any Z-Wave or WiFi devices that you install will have a range of five feet or so,

While I would definitely run CAT6 all over the house to a central point- some would call it future-proofing. I would also run RG-59 coax even though I have no immediate need for either. No box, just a couple of feet of the wire at known places behind the sheetrock. You can always cut the sheetrock to access the wire through an “old-work” box.

What would you want to do that you can’t already do with Z-wave or WiFi devices? In other words, why re-invent the wheel?