Minimal direct range
Homey is a Z-Wave Plus certified device. This means that Homey is independently tested to have a direct, bi-directional Z-Wave range of at least 40 meters in an open space. Note that walls and ceilings may impact the direct range of Homey negatively.
Extended range through mesh network
However, Z-Wave is a meshing technology. This means that each Z-Wave device that uses mains power (like a wall plug or built-in dimmer) can repeat signals from other devices in the Z-Wave network. Each signal can make up to 4 'hops'. This makes the effective range of Z-Wave much bigger, especially when you have several devices throughout the home.
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 Z-Wave device temporarily small, to prevent malicious actions. Always pair Z-Wave 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.