How to carry out the electrical installation for automation in a detached house?

Hello

I would like to ask how to carry out the electrical installation in a newly built detached house in order to have the possibility of automation in the future.
Assumptions:
- control of lighting, roller blinds, heating
- the distribution box is very small and cannot be enlarged (nor can anything be inserted into it)
- the traditional installation must function normally

Is it possible to make an additional distribution box (in a different place than the electrical box) for digital signals based on arduino/raspberry pi, from which a cat5 twisted pair cable would be drawn to each element? The boxes would have a circuit controlled by a traditional switch or a circuit communicating via twisted pair....
How to route the twisted pair? As a bus or star (to each point separately) ?

What are the other ways (wired)?

Experts on the subject will speak, but I will say from myself that I have 80% of my house smart and everything flies wireless. If I could do the installation from scratch, I would just add more twisted pair, to each computer/TV and camera.

Wireless systems (at an acceptable price) are not reliable.
I'm thinking of something like KNX but I'm wondering how to route the wires in the building. I will make the control unit and receivers myself (on microcontrollers)