Loosely coupled configuration for Home Assistant

This post will be short, but I hope it prove to be useful.

My home is getting more and more connected, and the number of my automations grows each passing month. Recently, I equipped my roller shutters with connected Somfy engines so they could roll down automatically when it's too hot in summer. Spoiler: given the current heatwave, it's a boon!

I naively created the following automation configuration:

- id: '1742926520608'
  alias: Close all shutters
  description: Close all shutters if it's already hot in the morning
  triggers:
  - trigger: time                                                      #1
    at: 07:00:00
  conditions:
  - condition: numeric_state
    entity_id: sensor.saint_julien_en_genevois_temperature
    above: 23                                                          #2
  actions:
  - action: cover.close_cover                                          #3
    metadata: {}
    data: {}
    target:
      entity_id: cover.all_shutters                                    #4
  mode: single

1. If at 7 AM local time
2. The temperature where I live is higher than 23°C
3. Close
4. All shutters

Note the entity ID cover.all_shutters: it's not an out-of-the-box entity. I explicitly created a group for it:

cover:
  - platform: group
    name: "All shutters"
    entities:
      - cover.left_shutter
      - cover.middle_shutter
      - cover.right_shutter
      - cover.bedroom_shutter
      - cover.office_shutter

I copied the same approach to switch all the lights off when I leave home. I soon realized there were flaws in this approach.

While the probability of adding more shutters is pretty low, I'll likely add more smart lights in the future. Every time I add one, I'll need to put it in the group. Also, I added lights in waves; I ID'd the lights in French at first, but later switched to English. As I renamed them all in English to be coherent, I had to update my dashboard to adapt to the new IDs.

Home Assistant already has everything to cater for the above, Areas. You can–and you probably should-assign every device to an Area. Once done, you can replace the target part of the automation with a list of area_id instead of entity_id.

- id: '1742926520608'
  alias: Close all shutters
  description: Close all shutters if it's already hot in the morning
  triggers:
  - trigger: time
    at: 07:00:00
  conditions:
  - condition: numeric_state
    entity_id: sensor.saint_julien_en_genevois_temperature
    above: 23
  actions:
  - action: cover.close_cover
    metadata: {}
    data: {}
    target:
      area_id:                                                         #1
        - office
        - bedroom
        - living_room
  mode: single

1. Now, Home Assistant closes all shutters that are in any of these areas

Areas tend to be much more stable than individual devices. How often do you add a new area to your home? Granted, an area doesn't explicitly map to a room, but I think that's a better approach than my original one. Home Assistant will now manage every new device of the same type added to the area, e.g., if you motorize a new shutter or add a new light.

There's one drawback to this approach. UI Tiles accept only a single entity ID. Thus, if you want to use the GUI, you must create a group as I did in my first approach.

In this post, I showed how you could replace the explicit grouping of devices by areas. It's the same idea of loose coupling we have in software, but applied to Home Assistant configuration.

To go further:

• Group
• Targeting areas and devices

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Originally published at A Java Geek on July 13^th, 2025