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Archived version · pinned v2026-09-27-r2

In-Home Notice for Household Members and Guests

Effective September 27, 2026 · Version 2.0 · Reference page. The Terms of Service control.

If you use a Terrestream sensor in a home where other people live, stay or visit, this page helps you tell them about it. You can share this page, or use the sample notice in section 8.

The Terms recommend telling the people who live in or visit your home about the sensor and what it measures (Terms §13.5). This page isn't legal advice.

1. What the sensor is

The Terrestream Indoor Air Quality Sensor is a small device with a screen. It measures the air in the room where it sits and shows the readings on its screen.

It is not a smoke alarm or a carbon monoxide (CO) alarm and doesn't replace them. This sensor doesn't detect carbon monoxide — keep your CO alarms.

2. What it measures

  • carbon dioxide (COâ‚‚);
  • particles in the air (PM1.0, PM2.5, PM4.0 and PM10);
  • a volatile organic compound (VOC) index and a nitrogen oxides (NOx) index;
  • temperature and relative humidity;
  • air pressure;
  • light level.

From these readings it also works out an overall air-quality index. The sensor reports its own status too, such as its firmware version, settings and Wi-Fi signal strength.

The full list of sensor parts is at /legal/sensor-compliance.

3. What it doesn't do

The Terrestream service does not record or process audio, video or images. Air readings are not direct observations of people and cannot reliably identify or count occupants.

4. What the readings can show

The sensor measures the air, not people. But the air changes when people are around, for example:

  • COâ‚‚ rises when a room is in use, especially with the door closed;
  • particles and VOCs rise with cooking, cleaning, candles or smoking;
  • humidity rises with showers and cooking;
  • the light level shows when lights are on or off.

The Terrestream service uses patterns like these to estimate things such as whether a room seems to be in use, the home's usual routines, when the home seems empty, sleep hours, cooking, cleaning, showers and open windows. These are estimates about rooms and the home, not about a particular person, and they can be wrong. We don't use them to make decisions about anyone.

Owners and co-owners can turn optional routine and occupancy estimates off or on in household settings. They start on for homes with a known location outside Quebec; Quebec homes and homes whose location is unknown start off until an owner or co-owner activates them. Ordinary air-quality readings, alerts and their detailed evidence are not disabled by this choice.

The separate presence and routine insight views are limited to the home's owner and co-owners. Air-quality alerts and their detailed evidence remain visible to all Family Circle members. That evidence may indicate cooking, cleaning or presence, and may include activities a member reports.

5. Where the readings go

5.1 Connected (the usual setup)

When the sensor is on Wi-Fi and linked to an account, it sends its readings to Terrestream's cloud service about every 15 seconds. The readings are stored under the owner's account and appear in the Terrestream apps and web dashboard. The Privacy Policy explains how Terrestream handles them and how long we keep them.

5.2 Local-only

Firmware 4.1.0 or later supports local-only mode through a compatible paired Home Assistant integration. Public availability of that integration is separate from the firmware capability; see the feature matrix. The sensor then stops sending readings to Terrestream. It still contacts Terrestream to check for firmware updates and to confirm that updates installed correctly, using its device ID and firmware details, and it gets the time from the internet. A factory reset turns cloud upload back on.

5.3 Without Wi-Fi

If the sensor isn't connected to Wi-Fi, it only shows readings on its screen. Nothing is sent over the internet.

5.4 On the home network

  • Bluetooth. The sensor uses Bluetooth during setup, with the Terrestream app or a web browser, and when the owner changes its settings in the app.
  • MQTT. If the owner turns it on, the sensor also sends its readings to an MQTT broker the owner chooses, for example one used by Home Assistant.
  • Home Assistant link. If the owner pairs the sensor with Home Assistant using the eight-digit code on the sensor's screen, the sensor announces itself on the home network and shares readings with that Home Assistant server over an encrypted connection. Other devices on the network may see it listed.

6. Who can see the readings

  • The owner of the Terrestream account the sensor is linked to.
  • People the owner adds through Family Circle. Members can see the home's rooms, current and past readings, alerts and insights for that home. They can see the names and email addresses of Family Circle members, including the owner, but not the owner's billing.
  • Only owners and co-owners see the home's coordinates and the separate presence and routine insight views. All Family Circle members see air-quality alerts and their detailed cooking, cleaning and presence evidence, as described in section 4.
  • Terrestream, to run the service, and the service providers listed at /legal/sub-processors, as the Privacy Policy describes.
  • Anyone the owner chooses to send data to, for example through MQTT, Home Assistant, webhooks or API tokens.

7. What to tell the people in your home

Reasonable notice usually covers these points:

  1. There's a Terrestream sensor in the home, where it is and what it looks like.
  2. It measures the air (section 2). The service does not record or process sound, video or images.
  3. Where the readings go (section 5) and who can see them (section 6).
  4. Readings can show patterns, such as when a room is in use, and the service makes estimates from them (section 4).
  5. It isn't a smoke or carbon monoxide alarm.
  6. Who to ask with questions, and where to read more: terrestream.com/legal/in-home-notice.

Tell adults in writing if you can. Explain it to children in words they understand. Use each person's preferred language where you can; this page is also available in French.

Use the sensor only in places where you have the right to do so. In shared housing, don't place it in someone else's private room without their agreement.

8. Sample notice

You can copy this notice, change it, or write your own. Using it doesn't by itself meet every local rule that may apply to you.

Air-quality sensor in this home

This home has a Terrestream air-quality sensor in [room]. It measures the air: carbon dioxide, particles, VOC and NOx indexes, temperature, humidity, air pressure and light level. The service does not record or process sound, video or images.

The readings go to Terrestream's cloud service under [owner's name]'s account. [If the sensor is in local-only mode, say instead: "The readings stay on this home's network."] [Owner's name] and the people they share the home with in the Terrestream app can see them. The readings can show patterns, such as when a room is in use.

It is not a smoke or carbon monoxide alarm and doesn't replace them.

Questions? Ask [name]. More information: terrestream.com/legal/in-home-notice

9. Rentals and shared housing

If you rent out your home for short stays:

  1. Mention the sensor in your listing as an air-quality sensor, list what it measures and explain that the service does not record audio or video.
  2. Put a written notice near the sensor. You can use the sample in section 8.
  3. Follow your booking platform's rules for devices in listings. They may be stricter than this page.

If you're a landlord or share a home, check the local rules before you place a sensor in space that someone else lives in.

10. Family Circle members

Family Circle members have their own Terrestream accounts and see the home in the apps and web dashboard. When someone accepts an invitation, they see what they'll have access to and how to leave. Members can leave at any time from Settings in the web dashboard.

Where invited-minor enrollment is available, teens aged 13 to 17 (14 to 17 in Quebec) may join through the guardian-confirmation and personal-acceptance process in Terms §2.2 and §8.8. Children under 13 (under 14 in Quebec) can't be added.

Everyone else in the home, including children and guests without an account, is covered by the notice described on this page. The Current Feature Matrix describes Family Circle roles.

11. Local rules

Some places have rules about devices in shared homes, rentals or workplaces. Check the rules where the sensor is used. This page is available in French at /legal/in-home-notice?lang=fr for people in Quebec.

12. Updates

We update this page when the sensor starts or stops measuring something, when where the readings go changes, or when Terms §13.5 changes.

13. Version history

  • September 27, 2026 · 2.0. Updated for the current sensor: the full measurement list, no audio or video processing, what the readings can show and who sees the estimates, local-only mode and the Home Assistant link, Family Circle (free, with age limits), and a new sample notice. Removed the wiretap references and the list of privacy laws.
  • June 1, 2026 · 1.0. Initial publication.

Earlier versions are kept at /legal/archive.

14. Related documents

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