Q: does use of apple homekit compatible items require an internet connection

my understanding is that it is "Wi-Fi" LAN - if remote control/monitoring, one would certainly need InterWeb connectivity

Google can be helpful with questions such as yours, as the built-in search may not work as one would expect

https://www.google.com/search?q=does+use+of+apple+homekit+compatible+items+requi re+an+internet+connection%3F&ie=utf-8&oe…

VS.

https://discussions.apple.com/search.jspa?facet=content&type=discussion&q=does%2 0use%20of%20apple%20homekit%20compatible…

Yes, and no.

If you only plan on using Apple HomeKit-enabled devices within your home, then all that is needed is an iOS (running iOS 8.1+) and a wireless network. However, some features will require a connection to iCloud, which will require an Internet connection.

And you will definitely require an Internet connection when attempting to access any of your devices from a remote location.