What is happening
Over the last several years, a category of devices marketed as indoor air-quality sensors and vape detectors has expanded into rental units. Brand names like Halo, IAQ Sensor, Verkada, Awair, Soter, and IPVideo sit on ceilings looking like smoke detectors. They are pitched as compliance and safety tools. Depending on model and configuration, what they actually do includes:
- Detect occupancy patterns; when you are home and when you are not.
- Pick up audio anomalies, including, on some models, short audio clips.
- Detect motion and sometimes count the number of people in a room.
- Send all of this back to a centralized dashboard the landlord or property manager controls.
Smart locks, smart thermostats, doorbell cameras, and smart hubs sit in the same category: devices that quietly produce a continuous record of when you come and go, what you do, and who visits you.
Why this is showing up in rentals
Landlords pitch these devices as compliance tools (no smoking, no vaping), as energy management, or as security. The actual incentive is information. A building with a centralized monitoring system can detect lease violations faster, push rent toward higher-friction tenants, and produce evidence for non-renewal disputes. The devices are inexpensive at scale, and the legal landscape has not caught up.
How to spot them
When you walk through a unit you are considering, look up. The most common signs:
- Ceiling devices that are not standard smoke detectors. A standard smoke detector is small (about four to five inches across), white, with a single LED. A vape detector or air-quality sensor is often larger, sometimes square or oval, with a vent grill and sometimes a visible logo.
- Brand markings. Look on the side of the housing for a small printed model number or a manufacturer logo. Halo, Verkada, IAQ Sensor, Awair, Soter, IPVideo, and Triton are common names worth searching by sight.
- Multiple "smoke detectors" close together. A vape detector and a real smoke detector are sometimes installed side by side. The vape detector is the larger one with a different shape.
- Smart thermostats with motion sensing. Some units pair a smart thermostat with occupancy detection. Read the model number and search it.
- Smart locks instead of physical keys. A smart lock keeps a log of every entry and exit.
- Anything that requires you to download an app. If the lease offer comes with "the building uses [app] for entry," that app is collecting data.
What to ask the landlord
Before you sign, ask in writing:
- What devices are installed in the unit, and what data do they collect?
- Who has access to that data?
- How long is it retained?
- Is the data sold or shared with third parties?
- Can the device be disabled or removed at the tenant's request?
A landlord who will not answer these questions clearly is telling you something.
Your rights in California
California has unusually strong audio recording protections. Recording audio in a place where someone has a reasonable expectation of privacy, which includes rented units, without the consent of all parties is generally illegal under the state's two-party consent rule. California also recognizes a constitutional right to privacy that has been interpreted to protect against intrusive surveillance.
That said, the law is unsettled when applied to ambient-sensing devices that claim not to record audio but do detect audio anomalies. Some local ordinances are stronger than state law. Berkeley, Oakland, and San Francisco each have rental-specific privacy provisions. This page is not legal advice. If you find a device and the landlord will not disclose how it works, talking to a tenant lawyer is worth the hour.
What to do if you find one
- Document it. Photos with date stamps, model numbers, location in the unit.
- Ask in writing. Email is better than a casual conversation, so you have a record.
- Report it on Housing Report Card. Open the report for the address and use "Report privacy concern." We aggregate anonymous, per-address counts of in-unit monitoring devices so the next renter sees what is installed before they sign.
- Talk to a tenant rights organization. SF has several, including the San Francisco Tenants Union and Causa Justa: Just Cause.
Why this matters
The argument for these devices is always: if you have nothing to hide, you have nothing to fear. That argument has never been honest. Surveillance changes behavior, and surveillance in your home changes who you can be in your own home. The relationship between tenant and landlord is already asymmetrical. Adding a real-time monitoring layer that reports back to the landlord makes it more so.
I built Housing Report Card to surface what is already public so renters have more information when they sign. I am against extending the same logic in the other direction, where tenants are continuously monitored without meaningful consent.
Before you sign
Search the address you are considering. If you have already seen something concerning installed in a unit, report it so the next renter sees it.