ᐅ Smart Home Planning – Is This Basic Approach Suitable?

Since my last thread, I have spent some more time studying the subject, and as the house planning is progressing faster than expected, I have already started making more concrete considerations regarding the "smart home" topic. I would like to share my ideas and plans, but also ask some fundamental questions to clarify my understanding.

The system will be implemented using KNX. For functions that I don’t want or “need” right now, I at least want to plan empty conduits (ducts) for future wiring. The system’s long-term expansion should then take place through these empty conduits or, if they are not available, via a wireless solution.

First, a few questions and statements about the basics, just so I don’t plan based on incorrect assumptions. Please correct me where I am wrong:

• A KNX system can be fully programmed on the actuators, fully through logic, or via a mix of both. However, the components always need to be parameterized, which can only be done with ETS.
• The logic engine runs on the home server, which communicates with the bus via an interface. The logic is based on the ETS project.
• Each controllable load or group is connected to its own power line running to the distribution board. This means, in the extreme case, one line from every socket and light fixture to the distribution board.
• Can bus cables be branched, or do I need a separate cable from each sensor to the distribution board? Is it enough to run one cable per room and lay empty conduits for possible future sensors, or do I have to pull cables right away?
• Does it make sense to control underfloor heating and a central mechanical ventilation with heat recovery system via KNX?

I want to carry out the setup and expansion of the system in multiple phases. Although I am technically and manually skilled, my knowledge of programming, electrical work, and electronics is not sufficient (yet) to handle such a project on my own. Therefore, the electrician/system integrator will perform the electrical and KNX installation and setup. Initially, only the basic functions will be implemented—for example, lights on/off or shutters up/down using specific pushbuttons—so the house can first be operated “manually.” The second phase will start after completion and include creating a visualization with smartphone control, programming scenes and automatic sequences using a logic engine (I am thinking of something like Edomi), integrating a central control panel (Android panel or touch display with Raspberry Pi), and a home server (NUC or thin client), as well as connecting other components such as an IP door intercom or remote controls. The final phase will be further system expansion as needed, for example with a weather station, outdoor and indoor cameras, humidity sensors and ventilation control, or integrating wireless components (e.g., window contacts).

The house will be a bungalow without a basement but with an attic, about 140sqm (1507 sq ft) of living space and an attached garage with a technical and storage room. The distribution board will be located in the garage to avoid clicking actuators inside the living areas. I have thought about what I want for the basic installation in the individual rooms:

Living/Dining/Kitchen:

• Multi-functional pushbuttons for lights and blinds; pushbutton in kitchen for under-cabinet lighting
• Presence detectors/light sensors in all three areas
• Several lighting groups in the living area, one group in dining, ceiling spots and cabinet underlighting in kitchen each as one lighting group—all dimmable
• “Multimedia sockets” switchable, possibly additional dimmable sockets in the living room
• Outdoor light sensor under roof overhang on south side

Entrance area/Guest WC/Hallway:

• Pushbuttons for lights; in WC multi-functional pushbutton for blinds and lights
• Presence detector/light sensor

Office and Children’s Rooms:

• Multi-functional pushbuttons for lights and blinds, lights dimmable
• “PC/multimedia sockets” switchable, rest possibly dimmable
• Presence detector/light sensor

Bedroom and Walk-in Closet:

• Bedroom multi-functional pushbuttons for lights and blinds, lights dimmable
• Sockets switchable and dimmable
• Presence detector/light sensor in both rooms

Bathroom:

• Multi-functional pushbuttons for lights and blinds
• Separate lighting groups above bathtub, shower, and sink—all dimmable
• Presence detector/light sensor
• Socket for mirror lighting switchable and dimmable

Utility Room:

• Pushbuttons for lights and blinds
• Presence detector/light sensor
• Water leak detector and shut-off valve
• Sockets switchable

Storage/Technical Room:

• Motion detector/light sensor

Garage:

• Multi-functional pushbuttons for lights and garage door
• Motion detector/light sensor

Additionally, preparations for a weather station, heating and ventilation control, wall panel, etc.

What would be a rough estimate of the cost range for this system, assuming average-quality components?

Quite a long post—I am sure something might be missing. But are there any major inconsistencies or nonsense here? Please correct if necessary.