This sensor returns the list of all open windows by checking all the windows sensors defined in a group.
template:
  - sensor:
    - unique_id: "1e186ee6108b450fbe0b60df5501ddd3"
      name: "Open Windows"
      icon: mdi:window
      state: >
        {% set open_windows = expand('group.windows') | selectattr('state','eq','on')
                            | map(attribute='name') | list %}
        {% if open_windows|length == 0 %}
            The windows are closed
        {% elif open_windows|length == 1 %}
            {{ open_windows[0] }} is open.
        {% else  %}
            {{ open_windows[:-1]|join(', ') }}{{ ', ' if open_windows|length > 2 else ' ' }} and {{ open_windows[-1] }}{{ ' are open.' if open_windows|length > 2 else ' are open.' }}
        {% endif %}
group:
  - windows:
    name: Finestre
    icon: mdi:window
    entities:
      - binary_sensor.portafinestra_cucina
      - binary_sensor.portafinestra_soggiorno
      - binary_sensor.finestra_camera
      - binary_sensor.finestra_seconda_stanza
      - binary_sensor.finestra_bagno
This Home Assistant sensor, named "Open Windows", is a template sensor designed to track and report the state of windows in your home. Here's how it functions:
Window Detection:
It checks the entities in the group group.windows and filters for those with the state on (indicating an open window).
Dynamic State Reporting:
This sensor is helpful for monitoring the open/closed status of your home's windows and providing a natural language summary of their state.
Even if I'll try to keep all this pages updated, products change over time, technologies evolve... so some use cases may no longer be necessary, some syntax may change, some technologies or products may no longer be available. Remember to make a backup before modifying configuration files and consult the official documentation if any concept is unclear or unfamiliar. 
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