Minimal direct range
Homey is a Zigbee certified device. This means that Homey is independently tested to have a direct, bi-directional Z-Wave range of at least 10-20 meters in an open space. Note that walls and ceilings may impact the direct range of Homey negatively.
Just like Z-wave, Zigbee was set up to allow household appliances to communicate with each other wirelessly. In particular, the low energy consumption and the repeater function makes them suitable for home automation applications. Zigbee uses the same wireless band as Wi-Fi and Bluetooth: 2.4 GHz. This means that devices can easily be certified and sold worldwide.
Extended range through mesh network
However, Zigbee is a meshing technology. This means that each Zigbee device that uses mains power (like a wall plug or built-in dimmer) can repeat signals from other devices in the Zigbee network. In practice, this means that the range and reliability of the entire Zigbee network increases with every device that you add. The technology itself builds the mesh network when devices are added to Homey. In addition, a signal from Zigbee can infinitely 'hop' to amplify it.
Limited range during pairing
Note: while pairing, a signal cannot 'hop' across the network. Also, for security measures, some devices pair in a special low-powered mode. This makes the range of that Zigbee device temporarily small, to prevent malicious actions. Always pair Zigbee devices close to Homey, then place them in the right place. Within 30 minutes, the new network routes will be automatically established, and the device will become active.