Zigbee is a standard that assumes communication at 75-100m indoors and 300m in the line of sight. (See Zigbee Alliance web site)
Zigbee can increase the communication distance by hopping between nodes instead of 1-to-N communication, so there is also a method to expand the communication range by installing a range extender.

When Zigbee is actually installed in equipment, the communication distance that can be obtained is affected by various factors. For example, the performance of the chip/module used (transmitting power, receiving sensitivity, etc.), equipment design (component layout, housing material, etc.), usage conditions (communication data volume, etc.), usage environment (indoor/outdoor, weather, etc.) , house layout and materials, noise, etc.).

Since module products have already been designed around wireless, it tends to be easy to obtain wireless performance when installed in equipment. Some of Silicon Labs' module products have already acquired Japanese technical standards.