As the title says, I’m wondering if I can integrate fibaro devices (for example the fibaro z-wave smoke detector) with home assistant without buying the fibaro hub? I want to use the aeotec z-stick 5th gen as the z-wave controller.
Yes, that’ll work.
Any Z-Wave Plus device will work with any Z-Wave Plus controller (stick).
Great! Many thanks for the clarification. I think adding that sentence to the z-wave getting started documentation would be helpful for many novice users. 
Though without Fibaro gateway no firmware updates will be possible… I believe.
Not only (as tink says) z wave plus but the older z wave devices too (my boiler switch is one such, but I would agree you should avoid those if possible). The major difference is the expiration on a patent (a ridiculously obvious one and therefore should not have even been granted patent status, by definition) the patent was for a manually operated switch to update another device across it’s operating medium (in this case z wave, but other mediums were affected) of the switch change in status.
Mirek’s point is also true, under ozw 1.6 you would be able to update the device firmware over the network. Provision for this is very limited at the moment without proprietary support (eg the fibaro hub) but it is being worked on and may arrive in 8-12 months
Hello everyone
It’s great to see this thread, as I was having the same doubt. I actually went ahead and bought a rebranded Sigma Designs stick and a Fibaro FGBRS-001, but I just can’t get them to pair in HA.
I click “add node” or “add secure node” and then click the button on the device and nothing works.
Anyone has tried this already?
i was having problems with a fibaro smart module. i could use it fine but i couldnt change the config values, so this i was using on a wall switch, and so i had to double toogle it. now with the POWER OF ZWAVE JS, i was able to have all the configs. all i had to do is, exclude node, and then ad it again! and VOILA! back in the game!
This might change with ZWave JS, the possible improvements also mention firmware updates, would be really nice to have this. see Github list ZWaveJS