Using HomeKit Groups vs Zones
As your smart home gains devices management of those devices can become somewhat cumbersome without the assistance of logical hierarchies and other organizational tools. These tools vary with the platform and app of your choice, but in the case of Apple’s HomeKit there are a couple of useful features in this area that are overlooked by many users.
I’ve discussed the effectiveness of using the Room system to keep your devices grouped logically, and how this grouping forms a fundamental part of the context used by Siri for determining which devices are being referred to in commands. In additional to Rooms we have Zones and Groups, which can each play a role in helping control and manage numerous devices.
Apple talks about Zones in it’s marketing material for HomeKit, so there is likely a little more familiarity with this grouping than Groups. However, it’s worth making the distinction clear, as the two types apply in different scenarios. Zones are a way to subdivide a home into logical areas, typically based on physical layout. The example often used is ‘Upstairs’ and ‘Downstairs’.
You can create a Zone from the settings page of any existing Room (except the Default Room) . In the Home app, tap Rooms at the bottom, then tap Edit. This puts the app into edit mode similar to the iOS home screen. From here tap the > button next to the room name at the top. You’ll see a Zone setting which you can tap on to select or create a Zone. Tap Create New to make a new one, and simply enter a name for the zone. This is a name that will be recognized by Siri, so make it easily understood.
Once zones are created they can be assigned to any given room via the same process, simply tap on the name of the Zone in the list from the Room settings and a check mark will appear next to it. You can actually assign a room to multiple zones, which provides further control possibilities. For example, you may have an “Entertaining” zone covering various living spaces and an outdoor area, while the outdoor area could also be in a zone for “Outside“.
So why would you do this in the first place? The primary reason for Zones is to allow for bulk commands to be sent to groups of devices to make home control easier. Creating a zone doesn’t have any impact on the device or room configuration outside the association to the zone, and it’s not presented in the Home apps device display in any way. It’s purely for use with Siri for issuing voice commands. Of course, third party HomeKit clients can use the zone data in other ways, such as providing alternative views of the home and so forth.
Here is where Zone differ from Groups. Groups actually change the view of the devices in the home app, providing a way of managing multiple devices that you may want to control as one. This perhaps seems less obvious, but it applies to lights in particular. Consider a track light setup, where you have three GU10 spots in a single light fitting. Do you want to have to turn them on individually, or just treat them as one light? Group allows this to be easily managed.
You can think of a Group as an alias for a set of devices. It effectively creates a new virtual device which replaces the member devices in the Home app’s view of a room, but still leaves those member devices untouched. This means you can refer to the devices either by the group name, or individually. Each device will still appear as normal in the list of devices for creating scenes and automations and can be individually selected and controlled via Siri. Note that those member devices cannot be added to Favorites while members of a group, though. Only the group can be added. This is fine though, as that’s really the point of creating a Group.
Similarly to Zones, you create a Group from the settings page of an existing device. You can access that page by either using 3D Touch to pop open the device, then tap the Settings button, or tap Edit in the top right corner of the screen, then tap the device to edit.
From the settings page, there is an option to “Group with Other Accessories...”. You may have to scroll down to see it. Tapping that will give you a name box and the normal list of accessories. Simply give the group a name (like ‘Track Light’) and select the devices to include.
Once created, the devices will disappear from the room view, and be replaced by the group. From the settings page of the Group, there is an Accessories option which allows you to add or remove devices from the group easily. At the bottom of the page is a red “Un-group Accessories” button, which will naturally delete the group altogether.
So we have two useful device grouping features in HomeKit with Zones and Groups. Zones is primarily for issuing bulk Siri commands to section of the home with no cosmetic change in the app, while Groups simplifies the in-app display of multiple devices which would logically to be used as one, such as lights which would be turned on and off together within a single room, as well as allowing issuing a Siri voice commands to that group of devices with a single name.