Hi,
I have built my house using KNX. Actually, the fact that it is mostly cable based makes this system super reliabe.
It also combines various trades, lighting, heating, etc and is supported by 500 manufacturers.
Together with a friend who has more than 20 years experience, we published an ebook on how to get started without any prior knowledge. There is a free version at https://knxtutorial.com/knx
In Germany, there are lots of people who plan and program the KNX system themselves. The actual wiring is carried out by a professional but the commissioning etc can be done by anybody. KNX requires a specific software (ETS).
As KNX is a global standard this procedure becomes more and more implemented. We have published an ebook about how to get started with KNX, ETS 5 and ETS Inside (cheaper version of it) and share best practices.