.....In your case of course you have KNX bus cabling in place and already have a load of KNX devices & your comfortable with it so go with that - take a look at our Bash-KNX package for 0710.....
Thanks for that, although I'm still unsure how z-wave devices are powered. I also think the scenario I have (individual power wires return to an electrical cabinet, where sockets and light fittings can be wired to on/off or dimming actuators as required) allows me to do what z-wave may be less good at - switch and control every individual socket and light fitting in my home. Also does z-wave require a separate controller? Once programmed KNX devices remember their function and status, even after power outage, and can operate as a self contained sub-system needing nothing more than the wall switches that mirror a more traditional wiring scheme operation (good for more technophobe family and guests) - I very much like the simplicity, low footprint, and inbuilt resilience of a programmed KNX system - even if installation is more onerous. Clearly this would be less suitable for a retro-fit.
The knowledge of another technology capable of integrating into my house project is all good. I will certainly consider z-wave for additional (as yet) unplanned functionality. The time you have taken to alert me to the possibility of z-wave is very much appreciated.
ZWave devices can be battery powered eg like the RA-Plus-W or a non-load baring wall dimmer and other devices like load baring wall switch/dimmers draw power from the main supply they control. Each mains powered ZWave device acts as a 'repeater' for the ZWave network and strengens it making it more resilient. If you fit ZWave enabled wall sockets and wall switches then they will all be controllable just as with KNX... in addition there are a range of 'plug-in' ZWave dimmer and switching modules that can just be plugged into any wall socket either to ZWave enable a standard wall socket or add ZWave very simply in a retro-fit situation.
Once you have added a ZWave interface to your LinuxMCE installation then that becomes the controller for your ZWave network allowing you to control your ZWave devices in any way you wish from any MD or Orbiter... or have a scenario do so automatically when certain criteria are met or a condition triggers one. If your Core crashes or there is some other technical issue that means it cannot communicate with the your ZWave devices then as long as you have mains power each device will still function normally ie press a wall switch and the light dim up/down. Even after a power failure your ZWave devices will retain there setup and config. So in that sense ZWave is as self contained as KNX is and can work on its own in a similar manner.
Happy New Year