Smart home planning - is this basically suitable?

After I have dealt a bit more with the subject since my last thread and the planning for the house itself is progressing faster than expected, I have already made more concrete considerations regarding the topic of "Smarthome." I would like to share my thoughts/plans but also ask some questions about the basic understanding.

The system is to be realized with KNX; for functions that I do not want or "need" at the moment, I at least want to provide empty conduits. The long-term expansion of the system should then be done via the said empty conduits or, if not available, with a radio solution.

First of all, some questions or statements about the basics, just so I don't plan under false assumptions, please correct me where I am wrong:

[*]A KNX system can be programmed completely on the actuators, entirely via logic, or a mix of both. However, the components always need to be parameterized, and that can only be done with ETS.
[*]The logic engine is located on the home server, which communicates with the BUS via an interface. The basis of the logic is the ETS project.
[*]Each switchable consumer or group is connected to its own power line running to the distribution board. That means, in the extreme case, a line from every socket and light to the distribution board.
[*]Can BUS lines be branched off, or do I need a line from each sensor to the distribution board? Is it enough to supply each room with one line and only lay empty conduits for possibly future sensors, or do cables have to be pulled directly?
[*]Does it make sense to control underfloor heating and a central controlled residential ventilation via KNX?

I want to carry out the setup and expansion of the system in several phases. I am technically and craft-wise experienced, but my knowledge in programming, electrical engineering, and electronics is (still) not sufficient to manage such a project on my own. Therefore, the electrical and KNX installation and setup should be done by an electrician/system integrator. Here, only the basic functions, e.g., light on/off or roller shutters up/down at button xy, should be implemented so that the house is initially operable "manually." The second phase then begins after completion and includes creating a visualization including smartphone control, programming scenes and automatic processes with a logic engine (I am thinking of Edomi here), integration of a central control panel (Android panel or touch display with Raspberry), and a home server (NUC or thin client), as well as the integration of other components such as an IP door system or remote controls. The last phase will be the expansion of the system as needed, for example, with a weather station, outdoor and indoor cameras, humidity sensors and ventilation control, or the integration of radio components (e.g. window contacts)...

The house will be a bungalow without a basement but with an attic, with about 140 sqm of living space and an attached garage with a technical and storage room. The distribution board would therefore be in the garage to avoid having clicking actuators in the living area. I have thought about what I would like for the basic installation in the individual rooms:

Living/Dining/Cooking:

[*]Multi-button switches for lights and blinds, switches in the kitchen for under-cabinet lights
[*]Presence detector/light sensor in all three areas
[*]Several light groups living area, one light group dining, cooking ceiling spots and cabinet under-cabinet lights each one light group – all dimmable
[*]Switchable "multimedia sockets," possibly additional living room sockets dimmable
[*]Light sensor outside under the roof overhang on the south side

Vestibule/Guest WC/Hallway:

[*]Switch for light, multi-button switch in the WC for blinds and light
[*]Presence detector/light sensor

Office and Children's Rooms:

[*]Multi-button switches for light and blinds, dimmable light
[*]"PC/multimedia sockets" switchable, rest possibly dimmable
[*]Presence detector/light sensor

Bedroom and Walk-in Closet:

[*]Bedroom multi-button switch for lights and blinds, dimmable light
[*]Sockets switchable and dimmable
[*]Presence detector/light sensor in both rooms

Bathroom:

[*]Multi-button switches for lights and blinds
[*]Separate light groups over bathtub, shower, and washbasin, all lights dimmable
[*]Presence detector/light sensor
[*]Socket for mirror lighting switchable and dimmable

Utility Room:

[*]Switch for light and blinds
[*]Presence detector/light sensor
[*]Water sensor and shut-off valve
[*]Sockets switchable

Storage/Technical Rooms:

[*]Motion detector/light sensor

Garage:

[*]Multi-button switches for light and door
[*]Motion detector/light sensor

Also preparation for a weather station, heating and ventilation control, the wall panel, etc.

Where would this system roughly stand in terms of cost if we assume average components?

Quite a long post, I am sure something is missing somewhere. But do I have any major inconsistencies or nonsense here? Please correct if necessary.

[*]A KNX system can be programmed entirely on the actuators, entirely via a logic, or via a mix of both. However, the components always have to be parameterized, and that can only be done with ETS.

Yes. But beware, misunderstanding: The logic runs either ON the actuators or on an external logic machine or an external server. Nowadays, every actuator comes with certain logic functions, e.g. gates, scenes, presets... KNX is not programmed OVER logic, apart from the fact that KNX is parameterized. In general, ETS is always needed.

[*]The logic engine is located on the home server, which communicates with the BUS via an interface. The basis of the logic is the ETS project.

Yes. Although Homeserver is a product from Gira (no idea if you mean that or generally a visualization/logic server).

[*]Every switchable consumer or group is connected to its own power line running to the distribution board. That means, in the extreme case, a line from every socket and light to the distribution board.

Also yes. Although for multiple sockets you can also use cables with 5 or more cores. Alternatively, there are flush-mounted actuators if a cable route would be too long or cumbersome. Popular here are decentralized LED drivers, flush-mounted blind actuators, or flush-mounted binary inputs.

[*]Can BUS lines be branched off or do I need a line from every sensor to the distribution board? Is it enough to supply each room with one line and only lay empty conduits for possible future sensors, or do cables have to be pulled directly?

With the green cable, you can do absolutely everything except a closed ring. Although the KNX line is often laid as an open ring to have a "backup."

[*]Does controlling underfloor heating and a central controlled residential ventilation via KNX make sense?

Those two have nothing to do with each other at first. You probably mean the valve actuators, right? Regarding underfloor heating there are two camps: 1. no control is needed because a proper hydraulic balancing is sufficient, and 2. wanting to control each room individually, regardless of whether that makes sense. Both have their justification. This has nothing to do with controlled residential ventilation anyway. I would simply let the controlled residential ventilation regulate itself except for possibly a party mode or cooking mode if it could be controlled room by room.

Then preparation for a weather station, heating and ventilation control, the wall panel, etc.

"Preparing" KNX has never worked in the long time I have been dealing with it. Either you do it right away or you never do it. Especially a weather station I would always implement immediately, because the functions it provides are essential, in my opinion. You don’t intervene in heating either, you just watch what it’s currently doing, same with the ventilation. You can prepare a wall panel, but you usually need LAN and/or power more than a bus line for that (although that never hurts).

Price-wise, it’s hard to say; you can have every component in many variants. Push buttons, for example, range from 50 euros up to four digits. Not quite as bad, but the same applies to actuators and sensors. Then there’s the parameterization, which you either have to pay for or trust yourself to do. It should be five digits though. I don’t know how extensive your market overview and KNX knowledge are, but depending on that, consulting a system integrator or someone who has done this before is recommended. Otherwise, things often go wrong that are no longer fixable.

Push button for light, multitaster for shutters and light in the WC

In my experience, that is never used. Why should it be, the light turns on by itself and the shutters also go up/down automatically. You can save money here. The same applies in the utility room.

Or only in the beginning until you get used to the automation and have broken the habits.

Where would this system probably cost approximately if we assume average components?

That depends heavily on the choice of components and also on the experience. In other words, the more service you need to buy in, the more expensive it will be.

It also depends on how, for example, the light should be dimmed and how many switchable channels you need.

Plan for a weather station right away. KNX pre-wiring works well in the attic, garden, garage. In the house, you already have to think carefully about where everything should go and then at least provide empty boxes with bus and NYM at those points, which will be connected later but are already pulled in during construction.

It's hardly possible to say anything about the price, you can have every component in numerous variants. For example, push buttons range from 50 euros up to four figures. Not quite as bad, but it’s similar with actuators and sensors. Then there's the parameterization, which you either have to pay for or trust yourself to do. It will probably be five figures. I don’t know how extensive your market overview and your KNX knowledge are, but depending on that, consulting a system integrator or someone who has done it before is advisable. Otherwise, things often go wrong that can’t be fixed anymore.

The complete planning, installation, and commissioning including parameterization will probably be "outsourced" to the electrician/system integrator. I would basically trust myself to do it if I put the effort in, but simply don’t have the time. And over the years, I have also learned that just because you can basically do something yourself, it often makes sense to pay a bit more and have an expert do it. The only reason why I want to deal with the matter in relatively more detail is that I dislike having projects planned and signing contracts without having a certain understanding of it myself.

In my experience, that never actually gets used. Why even bother, the lights turn on by themselves and the blinds go up/down automatically. You can save money here. Same goes for the utility room.

Or only in the beginning until you get used to the automation and drop your old habits.

Yeah, you’re probably right; my thought was more about redundancy. Sitting on the toilet in the dark because the presence detector malfunctions is just annoying. Logically, no high-priced glass push button would be installed there.

That strongly depends on the choice of components and also on the experience. Meaning, the more service you have to buy, the more expensive it gets.

It also depends on how, for example, the light should be dimmed and how many switchable channels you need.

The complete planning, installation, and commissioning including parameterization will probably be "outsourced" to the electrician/system integrator. If we take components in the mid-price segment, do you think we could manage with 10-15k? Or would it rather be 20,000+?

Plan for a weather station right away. Pre-wiring KNX works well in the attic, garden, garage. In the house, you already have to think very carefully about where everything should go and at least provide blank conduits with bus and NYM cable at those places, which will later be connected but should be pulled during construction.

Yes, I will definitely have the weather station prepared.
A walkable intermediate ceiling is planned as a storage space in the house. Would it not be possible to retrofit all cables there and pull them from above into the installation plane to the target point?

And over the years, I have also learned that just because you can do something yourself in principle, it is often sensible to pay a little more and have an expert do it.

That should be framed somewhere.

My thought was more about redundancy.

You can still have that without any switches/buttons in the named rooms.

Sitting on the pot in the dark should not be affected by the presence detector acting up, that’s just annoying.

Of course, I could say that this case almost never occurs, but yes, there is a small probability of about 1:100,000 (or so). You are still in the early stage and want to give up as little control as possible (like every beginner in this area). But that changes, and later you will think, "What was the button planned for again?" and "Why did I spend that money?"

But for all the skeptics: Tell me, do you still manually turn on the ignition in your cars? Because that could also act up?

Logically, no high-priced glass button would come into play here.

Certainly not. But every box, every insert, and every additional device costs money, which could also be spent elsewhere. Because let's be honest, after building the house, nothing is left anyway.

If we take components in the mid-price segment, do you think we’ll get by with 10-15k? Or will it rather be 20,000+?

How much does a car cost in the mid-price segment? And should it be a 3- or 5-door? I could calculate houses with comparable functions for 10K, 20K, or even 50K. There are simply too many unknowns. Alone the number of buttons is obviously uncertain.

The house should have a walkable intermediate ceiling as a storage space.

How can one imagine that? Are you building a whole mezzanine as a storage room?

Would it not be possible to lay all the cables there for retrofitting and pull them from above into the installation level to the destination point?

Depends on what you want to retrofit.

You can still have these without any switches/buttons in the named rooms.

How exactly? Multiple sensors?

Of course, I could say that this case almost never occurs, but yes, there is a small probability of 1:100000 (or so). You are still in the beginning stages and want to give up as little control as possible (like every beginner in this area). But that changes and later you will think "what was the button planned for again?" and "why did I spend the money".

You are probably right about that. Changing your mindset isn’t easy, although I’m probably quite flexible there. My partner reacted with a very skeptical and confused look to "Then we only have one central switch for everything in the living/dining/kitchen area" :D

H
ow much does a car in the mid-price range cost? And should it be a 3- or 5-door? I could calculate houses with comparable functions at 10K, 20K, or even 50K. There are simply too many unknowns. Even the number of buttons is obviously uncertain.

Ok ok, understood :p Then I’ll come back to that when I have something more concrete.

How can one imagine that? Are you building an entire mezzanine as a storage room?

Interesting idea but no haha As I wrote, it will be a bungalow, so by mezzanine I mean a solid ceiling (as opposed to a suspended or open-to-the-roof ceiling), which then serves as an additional storage room.

Depends on what you want to retrofit.

Well, switches and wall/ceiling sensors.