zlacker

The trick is to get a ZigBee device instead of a WiFi one. It's an inherently local-only protocol and you can make your computer a Hub with a $30 stick.

>>malerm+(OP)
ZWave is another option here too. I wouldn't recommend devices that don't have at least a "500 series"[0] chipset, but pretty much any device you'd buy today or moving forward will contain this or a newer chipset.

[0] https://www.silabs.com/wireless/z-wave/500-series-modules

>>nichol+e9
Yes, ZWave is good too, though I haven't seen many devices in the wild myself - this might depend on your local market.

>>nichol+e9
Z-Wave is also nice because it's in the 860/900 MHz band. Better propagation through walls and so much less contention than 2.4 GHz.