New house - help me getting started!

  • Hello!

    I'll hopefully start to build a house this year, and I'm considering adding a bit of "smart home"-thingies. I don't know so much about what's available, so I'm in desperate need of some tips!

    I'm not quite sure what I want to do (partly because I don't know what you can do). Primarily I want to be able to control the lighting in the house (turn off all lights with one button, have special themes, be able to reassign what a light switch does...). Also, the little hobby-tinkerer in me want to add some mySensors to the mix, already got a lot of the hardware for that.

    But, I suppose there has to be some "main" network managing the whole thing, to which the mySensors connect to. Is that right? If yes, then the big question(s) is (are): What system should I use (or what systems are available)? Should I go for a wired or wireless system? Should everything (lights etc.) have cables to the "electric central" of the house?

    Please point me in the right direction, so I know where to look!

  • Hero Member

    @MarcusG I suppose someone more knowledgeable then me will probably give a more detailed answer, but my 2c:
    Mysensors is not that great for inwall light switches. the main problem is, well, the mains...
    it is very tricky and dangerous to make a very small ac/dc transformer that can fit and work inside the wall. no one here managed to do it yet although several are thinking about it.
    if you add extra wires to any light switch i guess that shouldn't be a problem but it will increase your BOM for the house. You can also mix together several systems, like z-wave for lights and mysensors for everything else.
    You also need a controller. Domoticz, OpenHAB and Vera seems to be the most popular but have a look at the controller section. No controller is perfect, so you need to see which one fits the best to your use case.

  • my 2c : wire everything to your meter cabinet and you can always do what you want

  • Might have been a bit vague, I meant that I need help choosing a good "base system" for the house (which would control for example the lights). If I decide to build a "smart" home the important functions like lightning have to be rock solid and no tinkering involved (except initial setup and configuring scenes). The tinkering part for me would be mySensors, I would use it to create input controls, a few sensors here and there... Nothing "important" with mySensors, just fun to have stuff which doesn't matter if it stops working.

    Still a bit confused, so just to be sure I'll start with making this clear for me, so... Is this correct:

    1. For sensors and inputs (like buttons and switches) there exists a few different "protocols" (MySensors and Z-Wave being two of them)
    2. Controllers (Vera, Domoticz...) is the CPU for everything, and needs to support all the different protocols one uses in the house (which I suppose should be limited to as few as possible).

  • Hi, like someone mentioned above no controller is perfect but I can only tell you what I'm using for the same purposes as you intend, Lightning, Curtains, Irrigation en a couple of sensors.

    I've been running Domoticz on a Raspberry pi for over a year now with great pleasure. Together with a RFXCOM transeiver which is able to send 433mhz signals to wide range switches etc.

    For Z-wave there are USB-dongles or shields that can be easily attached to the Rasberry Pi. Besides that I have an Arduino Uno attached to the pi to act as a Mysensors gateway.

    As I said I'm not sure if this is the best way to go, but it fits my needs perfectly. Accept for the transeiver all the hardware is relatively cheap, easy to get and low on power consumption.

  • Hero Member

    @MarcusG you got it right....
    Just a little more of my vast knowledge with failures 🙂

    1. If you go z-wave (which is not a bad option, all things considered, but not cheap), try to get everything from the same brand. It works better. like Aeonlabs or Fibero. There is also a new standard Z-Wave+ which will probably make anything not Z-Wave+ Obsolete very quickly so you might want to take this into consideration.
    2. Domoticz worked very well with both Z-Wave and MySensors. When you decide on the architecture you go with, try to verify if everything you want is supported by the controller. For example I had a Z-wave AirCon remote control (an obsession of mine, it seems) from a respectable company that was only supported by their device. Nothing else.... 100$ just pafffttt disappeared.
    3. What @didi said :-). if you can do that - it will simplify your life. There are still all kinds of considerations - do you wire for 220v or for 5v (and then you face the problem of drop in current or something) or for 24v and step down or whatever - not an expert just remember reading about this. As this was never an option for me I didn't put too much thought into it.

  • First of all choose if you want to go wire or wireless.
    But even by wireless (433, 868, z-wave, enocean, zigbee, 2,4Ghz...) you might need power lines for motors, actuators, pumps, blinds...
    First of all write down what all you want to control, and based on this list try find the best system. I would go with wired system on beginning, and add wireless stuff for unreachable or outside controlled parts.

  • Thanks for the feedback!

    I think it shouldn't be too expensive to wire everything (read: at least all lighting and maybe all light switches, not sure if I'll do anything else a.t.m.) to the meter cabinet.

    a. What systems (protocols by my above definition...) are available if I go the wired way?

    Moshe: "There are still all kinds of considerations - do you wire for 220v or for 5v (and then you face the problem of drop in current or something) or for 24v and step down or whatever".
    b) drop in current, what's that?
    c) I suppose you run "normal" wiring to the lighting. Normally 220V, but I suppose it's possible to rewire in the meter cabinet if need be...
    d) What kind of cable should one use for "control wires", to switches, sensors and so on? Depends on what system ones chooses? Cat6?

  • @MarcusG Drop in current is the loss of electricial current running through the wires in your house/project. Think of it as current that is there but not available due to it being used .It is a result of the resistance the wire size creates by the size of the copper lines the current is running thru. The smaller the lines the higher the loss. Formula is resistance divided by voltage = current, if you use wire resistance then result is wire current losss.
    Usually combated by increasing the diameter (size) of the wire and or using higher voltage. ie, 24 volts instead of 5 or 120 volts instead of 24. Of course there are all the different costs to balance changing voltage to manage electricial current , but you have to take the distance in to consideration.

  • Admin


    If you are going with wired, then look at an RS485 bus (If you are going to do your automation yourself.) Otherwise look at what is readily available..

    have you seen this site?

  • Again, thanks for the replies! I've been reading your comments and trying to decide exactly what I want to do.

    (There's a summary below to all the text 🙂 ... )

    First, lights: This is really the only thing I really want and think actually would be useful to have. I want to be able to control all lights, to be able to have an all-lights-off, be able to program scenes etc. I also want to have the ability to operate the light by normal switches, and not have a setup where the house is pre-build for a specific system (which may be obsolete in 5, 10, 20, 40 years? I'm gonna live there for a while...). I suppose the best option is to wire everything to the meter cabinet. Then I can wire without any smart things, for example if I can't afford it now or if someone later want to remove the smart things. I can also add whatever system in-between the switch and light I want to.

    Second: I want to add a few mySensorthings just because I think it's fun. For example some "extra mood light" with LEDs. Unlike the normal light in the house (the "first" above), it's OK if these fail to work because the system crashes. Also, sensors for light, wind, rain etc might be nice to. To make powering all these systems easier, I'm thinking about installing a 24V or 48V power system in the house (at least 24V to be able to provide the power to run hundreds of LEDs, if need be). Powering the arduinos just requires a simple switch regulator.

    Third: If I want a few other things besides lightning and my own mySensors-thinkerings (doorbell, open garage door etc), I'll go with Z-wave for those. I don't really think I want too much smart things in my home besides lights (but it's hard to know what's good to have and what the tech nerd in me thinks would be nice to have...). Therefore, I will not install a wired system.

    I haven't decided on the controller yet, but probably Vera or some Raspberry pi-friendly open source thing...


    • all light wires + switches to meter cabinet for flexibility
    • power bus of 24V or 48V for my own arduino-things
    • if need be to add something else, I'll go with Z-wave
    1. Is the above correct and a good plan?

    2. Do anyone have any tips for relays to use for the lights in the meter cabinet?

    • it has to support having the physical button "always work", so I can use the lights even if the smart system for some reasons decides to not work
    • somehow I need to be able to trigger it from the controller (I've not decided on the controller yet, though, but probably either a Vera of some kind or raspberry pi-friendly open source-variant)
    • as I probably will have the controller in the meter cabinet, it maybe would be good to have wired control over these relays, seems a bit silly with wireless for a few decimeters...
    • I suppose it should be something like this (but not with Insteon?):
    1. Power bus, 24V or 48V, and pros and cons with either?

    2. Power bus: what type of connector would you recommend? It should be fairly small so it's not to noticeable on the walls, as I suppose I should add connectors a little here and there (up close to the ceiling/by the star/beside normal power connectors for LED lighting, by the windows for light sensors/plant water thingies...)

  • Hi,
    I'm in the same situation as you, designing future house electric system.
    Routing all the wires to the main cabinet (fuse box) is overkill since you can not wire a two position switch (in the room) and automation (at the panel) in such a way that they can work together, you either wire them in parallel and then the automation can not turn the light off if the room switch is on, or in series in which case the switch can not turn on the light if the automation failed. The only way to use it would be by using Push-Button like switches (doorbell switches) in parallel with the automation, commanding some type of step relays, but in that case the price is way high for wires and relays.
    My approach is to take both light leads to a larger light switch box in the room, plus some 12V rails, there I have some 12v-5v dc-dc reg, Arduino, relay board, pushbuttons and confirmation leds, plus radio. The system's top priority it turning lights on/off, I'm also considering adding another Arduino in ther for the radio communication, just to be sure the main Arduino does not crash and leave me in the dark.
    As relays for lights I use the aliexpress cheap relay boards with Songle 220V 10A rated relays, my CFL and LED lights take 200W max, which is under 1A, so the relays should last a long time.
    I've chosen the 12V low power buss for the cheap and reliable 12v-5V DC-DC step converters. You may go with 24V if you find the right voltage converters for a good price.
    For the sensors I leave the cable tubing out of the wall a few inches, and after painting I cut to the surface level and glue (silicone) a small box that sticks out with holes on top and bottom for better airflow. Heck I even have some dead end cable tubes in the walls for some DS18b20 in wall temperature probes, useful on exterior walls to prevent dew knowing the inside temperature and humidity.

    PS. Add some tube to the radiators if you use such things for heating, might be useful for monitoring in/out temps, and correlated to some electric motor ball valves you can have heating zones in your system.


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