Hello dear community,
we are just beginning to explore the topic of Smart Home and I would appreciate your opinions on our current (early) planning.
Starting point:
- New build of a single-family house with a general contractor, approximately 160m² (1720 sq ft) of living space, 3 children’s bedrooms + home office
- Building permit / planning permission currently pending; construction start planned for spring
- I would like to create and customize the Smart Home logic myself; I am willing to study it in depth and enjoy the topic
Planned automation:
(1) Starting with very simple functions such as automatic lights on/off with presence detection for 6 rooms (WC, utility room, storage room, upstairs and downstairs hallway, staircase)
(2) In the guest bathroom, music should also turn on with presence detection and possibly increase ventilation slightly
(3) Throughout the entire upper floor (6 rooms), a night light should turn on at night when movement is detected (e.g., for nighttime bathroom visits)
(4) All blinds / shutters (16x) should be controllable individually (based on time or sun position)
(5) All windows/doors (17x) equipped with tilt sensors to detect open windows, e.g., warnings in case of rain, alerts when the house is left, simple alarm system
(6) Front door with electric lock and video doorbell
(7) Underfloor heating digitally controllable per room
(8) Simple outdoor automations for lighting (motion sensors) and cameras
(9) We want to avoid push buttons wherever possible; we prefer voice control or even better fully automated operation without any interaction
Still open / to discuss:
(1) Hot water and circulation only at certain times or when someone is at home (is this financially worthwhile with efficient heat pumps at all?)
(2) CO2 sensors, for example in the home office, to control ventilation based on presence/absence (e.g., ventilation set to maximum if I quickly leave for coffee and the CO2 value exceeds a certain threshold)
(3) Networked smoke detectors as an alarm system and to hear a fire alarm from the ground floor in the bedroom (?)
(4) Robot vacuum cleaner in the hallway that starts automatically when entering or leaving the house (to clean dirt in the hallway)
(5) Lawn mower that only operates under certain weather conditions and when no one is in the garden
(6) Automatic garden irrigation depending on the forecasted weather (cistern planned)
(7) Towel heater in the bathroom to switch on/off selectively (e.g., warm bathroom in the morning, warm towels right after showering)
(8) "Public address" system from the kitchen to all children’s bedrooms (“Dinner is ready”)
Questions:
(1) Do the planned automations make sense so far?
(2) Do you have any comments and/or recommendations regarding the open points? Are there any interesting automations we are missing?
(3) What is the best way to plan such a Smart Home with a general contractor? They only offer a lump sum package through their electrician with a “Smart@Home” system. I would prefer to plan with a specialized electrician. Is it possible to exclude this trade from the contract and award it separately, or would this cause problems?
(4) Am I correct in assuming that a KNX wired system would be suitable for the above use cases? As a comparison, I roughly calculated Homematic IP flush-mounted installation costs between 5,000–10,000€ as an additional investment (besides the standard general contractor electrical work). How could I make a reasonable cost estimate for KNX? Background: If a wireless solution costs me 10,000€, I want to carefully consider whether I am willing to spend 30,000€+ on KNX.
(5) Is it realistically possible in such a Smart Home to almost completely do without push buttons in the rooms? (We find voice control much more convenient and currently use a lot of Alexa)
we are just beginning to explore the topic of Smart Home and I would appreciate your opinions on our current (early) planning.
Starting point:
- New build of a single-family house with a general contractor, approximately 160m² (1720 sq ft) of living space, 3 children’s bedrooms + home office
- Building permit / planning permission currently pending; construction start planned for spring
- I would like to create and customize the Smart Home logic myself; I am willing to study it in depth and enjoy the topic
Planned automation:
(1) Starting with very simple functions such as automatic lights on/off with presence detection for 6 rooms (WC, utility room, storage room, upstairs and downstairs hallway, staircase)
(2) In the guest bathroom, music should also turn on with presence detection and possibly increase ventilation slightly
(3) Throughout the entire upper floor (6 rooms), a night light should turn on at night when movement is detected (e.g., for nighttime bathroom visits)
(4) All blinds / shutters (16x) should be controllable individually (based on time or sun position)
(5) All windows/doors (17x) equipped with tilt sensors to detect open windows, e.g., warnings in case of rain, alerts when the house is left, simple alarm system
(6) Front door with electric lock and video doorbell
(7) Underfloor heating digitally controllable per room
(8) Simple outdoor automations for lighting (motion sensors) and cameras
(9) We want to avoid push buttons wherever possible; we prefer voice control or even better fully automated operation without any interaction
Still open / to discuss:
(1) Hot water and circulation only at certain times or when someone is at home (is this financially worthwhile with efficient heat pumps at all?)
(2) CO2 sensors, for example in the home office, to control ventilation based on presence/absence (e.g., ventilation set to maximum if I quickly leave for coffee and the CO2 value exceeds a certain threshold)
(3) Networked smoke detectors as an alarm system and to hear a fire alarm from the ground floor in the bedroom (?)
(4) Robot vacuum cleaner in the hallway that starts automatically when entering or leaving the house (to clean dirt in the hallway)
(5) Lawn mower that only operates under certain weather conditions and when no one is in the garden
(6) Automatic garden irrigation depending on the forecasted weather (cistern planned)
(7) Towel heater in the bathroom to switch on/off selectively (e.g., warm bathroom in the morning, warm towels right after showering)
(8) "Public address" system from the kitchen to all children’s bedrooms (“Dinner is ready”)
Questions:
(1) Do the planned automations make sense so far?
(2) Do you have any comments and/or recommendations regarding the open points? Are there any interesting automations we are missing?
(3) What is the best way to plan such a Smart Home with a general contractor? They only offer a lump sum package through their electrician with a “Smart@Home” system. I would prefer to plan with a specialized electrician. Is it possible to exclude this trade from the contract and award it separately, or would this cause problems?
(4) Am I correct in assuming that a KNX wired system would be suitable for the above use cases? As a comparison, I roughly calculated Homematic IP flush-mounted installation costs between 5,000–10,000€ as an additional investment (besides the standard general contractor electrical work). How could I make a reasonable cost estimate for KNX? Background: If a wireless solution costs me 10,000€, I want to carefully consider whether I am willing to spend 30,000€+ on KNX.
(5) Is it realistically possible in such a Smart Home to almost completely do without push buttons in the rooms? (We find voice control much more convenient and currently use a lot of Alexa)
S
Schnubbihh4 Jan 2024 11:17Sahitaz schrieb:
First of all, congratulations! Seriously! You have understood the core idea of SmartHome better than 90% of others (including many manufacturers of supposedly smart products)!!! Thank you very much for your honest feedback!
Sahitaz schrieb:
Most of your requests are ABSOLUTELY reasonable! The only ones I would question are door sensors if you mean interior doors, as I really see little benefit there (I assume you don’t mean interior doors, but I have definitely seen/heard of that before). However, you can still benefit from it, although that goes quite far. They indeed only refer to the front door and patio door. Nothing is planned for interior doors.
Sahitaz schrieb:
The heating control is questionable, but that depends on your heating system and whether it is worthwhile or not. We plan to install a Tecalor (Stiebel Eltron) THZ 5.5 eco. KNX integration is basically possible, with a heat pump plus central mechanical ventilation combined. I think we will hardly adjust the underfloor heating, but room temperatures should be digitally controllable (probably the actuator at the heating manifold is sufficient, I assume?).
Since the heat pump also includes ventilation and possibly passive cooling, I see more interesting use cases where I would consider general control. The exact use cases still need to be defined.
Example: If at least one window is open in the morning and the outside temperature is lower than the inside temperature, then the exhaust fan runs at maximum to draw in fresh air from outside (something like that...).
Sahitaz schrieb:
I would also like to question the price comparison between Homematic and KNX. Is it really 5–10k for component costs alone? An electrician who installs and programs/configures also charges money here. Yes, that’s just material costs. With some experience, programming can be done yourself with these parts. Installation in the larger flush-mounted boxes should probably not be a cost factor (I assume?).
Sahitaz schrieb:
In what I consider a standard reference for home automation with KNX, there is an example calculation that I recall covering a similar or even larger scope of wishes involving KNX and DALI, listing costs of about 15k, although the prices are a few years old and the scope should be properly compared instead of relying on memory. The initial costs for KNX are certainly high compared to most other systems. But the more you network, the more cost-effective it becomes overall. €15,000 would be completely within my budget. I am more worried about costs in the range of €40,000–50,000 or more, in which case the whole project would probably have to be dropped for budget reasons. (My better half would not agree to that either.)
Sahitaz schrieb:
So, this should cover (1) and (4).
(2) Consider keyless entry, mailbox monitoring, calendar for waste disposal or other topics, power measurement for circuits like washing machine or refrigerator to detect if finished or defective, or similar, triggering scenes (Sleeping -> no doorbell, Showering -> towel radiator, … just ideas not must-haves!!! Interesting, I will add that to the wish list!
A brief addendum: the €15,000 included component costs (including €1,000 for the software itself) for programming KNX yourself, so this was without an electrician. This was meant only to compare with your Homematic price estimate. However, you definitely need to compare the scope of each system!
The example calculation included dimmers, switching actuators, roller shutter actuators, power metering, window contacts, temperature sensors and controllers, and so on. That is already a reasonable scope for a single-family house.
Perhaps (though I cannot judge) this is more comprehensive or complete than what you included in your Homematic estimate. I don’t know how detailed your analysis was.
I installed Homematic for my parents for their roller shutter control, so I don’t want to speak badly of it. It works flawlessly, and for purely controlling roller shutters, it was definitely cheaper and less effort than KNX. But I want to point out that the more features you implement, the smaller the price difference becomes, and depending on priorities and requirements, the difference may even reverse—or it may not.
The example calculation included dimmers, switching actuators, roller shutter actuators, power metering, window contacts, temperature sensors and controllers, and so on. That is already a reasonable scope for a single-family house.
Perhaps (though I cannot judge) this is more comprehensive or complete than what you included in your Homematic estimate. I don’t know how detailed your analysis was.
I installed Homematic for my parents for their roller shutter control, so I don’t want to speak badly of it. It works flawlessly, and for purely controlling roller shutters, it was definitely cheaper and less effort than KNX. But I want to point out that the more features you implement, the smaller the price difference becomes, and depending on priorities and requirements, the difference may even reverse—or it may not.
Schnubbihh schrieb:
A Tecalor (Stiebel Eltron) THZ 5.5 eco will be installed. KNX integration is basically possible, and the system combines a heat pump with central ventilation. I think we won’t adjust the underfloor heating much, but room temperatures should be digitally controllable (I assume the actuator at the heating circuit valve is probably sufficient for this).
Since the heat pump also includes ventilation and possibly passive cooling, I already see more interesting use cases here, which is why I would consider general control. The exact use cases still need to be defined.
Example: If at least one window is open in the morning and outside temperature is lower than inside temperature, then maximum exhaust fan to draw in fresh air from outside (something like that…) There is a widespread opinion in this forum about individual room control and heating actuators (an opinion I share, by the way). The usefulness of these is especially questioned when combined with a heat pump and underfloor heating. Highly insulated houses with slow-reacting underfloor heating systems and low supply temperatures due to the efficient operation of heat pumps usually do not allow significantly different room temperatures. Therefore, it is more common to adjust the flow rate and supply temperature for the entire system (which must be clarified with the heating engineer). This makes it possible to do without switching actuators and valve actuators — but of course, then no individual room control is possible anymore.
Schnubbihh schrieb:
Yes, just material costs. With some experience, programming these devices can be done independently. Installation into the larger flush-mounted boxes probably shouldn’t be a major cost factor (I assume?).
€15,000 (about $16,000) would be completely reasonable for me. I’m more concerned about costs in the €40,000–50,000 range (about $43,000–54,000) or higher, which would likely cause the whole project to be dropped due to budget constraints. (My partner wouldn’t agree to that either.) I first just wanted to try to make a comparison so that apples are compared with apples. Meaning comparing material to material or complete systems including installation on the same basis. To be fair, it must be said that getting familiar with KNX parameterization is significantly more demanding than with Homematic, and this should not be underestimated. So an electrician-installed KNX system could indeed fall within the cost range you mentioned—that’s hard for me to estimate. But a complete Homematic system installed by an electrician won’t remain under $10,000 either.
S
Schnubbihh4 Jan 2024 11:47Sahitaz schrieb:
There is a widely held view in this forum regarding individual room control and heating actuators (a view I also share). The usefulness of this, especially in combination with heat pumps and underfloor heating, is strongly questioned. Highly insulated houses with slow-reacting underfloor heating systems and low supply temperatures due to the efficient operation of heat pumps generally do not allow significant differences in room temperatures. Therefore, it is usually possible to adjust the flow rate and supply temperature for the entire system (but this must be clarified with the heating installer). This would make it possible to avoid the use of switching actuators and control valves. However, this would definitely not work on a per-room basis anymore. How should one handle a situation where we want 19°C (66°F) in the bedroom but 22°C (72°F) in the living room? That should be possible, right, or am I misunderstanding something?
Sahitaz schrieb:
I just wanted to try to draw a comparison so that apples are compared to apples. Meaning comparing material to material or the complete system including installation against the same. To be fair, it has to be said that getting familiar with KNX programming is considerably more complex than with Homematic, and this should not be underestimated. So a KNX system installed by an electrician could realistically fall into the price range you mentioned, but I find this difficult to assess. However, a Homematic system installed by an electrician will also not stay under $10k (USD). Understood, I will need to study more in depth how much of the KNX programming I can realistically do myself and where I will need an electrician’s help.
S
Schnubbihh4 Jan 2024 12:01Maybe a silly question, but is individual room control possible with a central ventilation system (Tecalor THZ 5.5 ECO)? According to the user manual, you can only select levels 0-3 for the ventilation, but I assume this always applies to the entire house? I would like to be able to control the supply air and/or exhaust air (bathroom) separately. Is something like this possible?
J
jens.knoedel4 Jan 2024 12:07Schnubbihh schrieb:
How should this be handled if we want 19°C (66°F) in the bedroom but 22°C (72°F) in the living room? That should be possible, right, or am I misunderstanding something?You can plan for that when designing the heating system. Fundamentally, a difference of 19 to 22°C (66 to 72°F) in a new build is already close to the limit of what’s achievable.In that case, it might be better to sleep with the window open to keep the room cooler…
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