io-homecontrol

io-homecontrol is a shared 868 to 870 MHz radio standard used by Somfy, Velux, and a long list of window, shutter, and heating manufacturers, with 128-bit AES encryption and, most importantly for automation, two-way communication. When a gateway sends a shutter to 40 percent, the motor answers with where it actually ended up. That single property is the line between a cover entity that can be trusted in a condition and one that can only be commanded.

Strengths

• Real position feedback. Motors report their state, so Home Assistant shows a position rather than an assumption, including after someone uses a wall remote or a handset instead of the app. Worth one caveat: Home Assistant notes that some Overkiz devices do not broadcast changes on their own, and those refresh when the vendor app asks for a status update, so a given device’s state can lag even though the radio itself is two-way.
• Cross-brand by design. The same radio carries Somfy shutters, Velux roof windows, Atlantic heating, and partner equipment, so one gateway covers a mixed house.
• Encrypted and paired. Commands are authenticated and encrypted, which matters for something that physically opens a building.
• Retrofit paths exist. A wired shutter can be brought onto io with a receiver module behind the switch, or by swapping the motor, without rewiring the house.

Trade-offs

• A gateway is mandatory. Home Assistant never talks to an io device directly. It talks to a TaHoma, Connexoon, or another Overkiz gateway, which owns the pairings; lose the gateway and you lose the integration, not just the app.
• Pairing is a manufacturer process. Devices are enrolled with the vendor’s app or an installer tool, so adding hardware is a commissioning job rather than a Home Assistant one.
• Not sold everywhere. io-homecontrol is a European standard: North American Somfy hubs and motors are RTS and Zigbee, so a design that assumes position feedback has to check which regional variant is actually being bought.
• The gateway is the bottleneck. Gateways hold a short execution queue, so a scene that moves every cover at once needs staggering regardless of how capable the motors are.

io-homecontrol in Home Assistant

Support arrives through the Overkiz integration, which covers Somfy TaHoma and Connexoon gateways as well as the white-label vendors on the same platform, and through Velux for the KLF 200 interface. Somfy and Rexel gateways additionally expose a local API, which removes the cloud round trip for covers, lights, and switches, though scenarios and climate entities remain cloud only. In a Selora install, io-homecontrol is the protocol to specify when shading has to participate in real automation rather than being pushed open and closed on a schedule.