I'm about to start thinking about building house.
And I would like to prepare myself for it. Basically, the idea is to get as much prepared as it's possible before I decide to lay cables.

The question is: what to go for, to have:

• future proof house, with possibility to change automation technology in 10-20 years
• known and cheap, open standard
• ability to change controllers (like domoticz) to something else

Currently my idea is to lay almost every possible power (AC) cable to one box in garage and there have an switch-relay board controlled by...?
I know the EIB/KNX standard, which costs a lot and is not really easy to maintain by own.

RS485 - sounds good in theory, but have a limit of devices on bus

I also had idea to have relays behind sockets and switches, but then I will hear the clicks every time.
Also, I'd like to use doorbell-like switches, so I can simply press it to turn on one light and hold to turn on/off all lights etc.

Any ideas and knowledge share, guys?