While the new “Home” panel in the iOS 10 Control Center is a pretty handy feature for users with HomeKit accessories, it’s worth keeping in mind that it’s accessible by default even when your iPhone is locked. As with issuing Siri commands, HomeKit will still require authentication before controlling things like door locks, but if you want to ensure that other accessories like lights and thermostats can’t be controlled from the lock screen, you’ll be happy to know that you can disable Home control without having to deny lock screen access to the entire Control Center.
As with other Lock Screen security settings, you can find the option for this under Touch ID & Passcode in the iOS Settings app. Turning off Home Control from here will remove the Home panel from the Control Center on the Lock Screen entirely, while also requiring authentication for ALL Home-related Siri commands, similar to the way in which door lock controls always work.
Alternatively, if you only want to limit control to specific accessories, keep in mind that the Control Center panel only shows Accessories and Scenes that are marked as “Favorites” in the Home app, and limits that to only the first nine Accessories, and first eight Scenes — so you can remove specific Scenes and Accessories from being available in Control Center by either removing them as Favorites or ensuring that they’re not at the top of those lists.