There’s also an FAQ on coverage for a large house. As both @kevin and @ashutosh1982 mentioned, device selection and placement are key.
We should note that the advertised maximum range for any of the protocols is always based on clear air on a dry day. It’s much longer than you would get inside a typical home. The usual rule of thumb for a zigbee or classic Z wave device indoors in a typical residential setting is around 14 m/40 feet for one “hop.” And longer for Z wave plus, but still only about 20 m/60 feet.
That’s because all kinds of things degrade signal, including walls.
The good news is that both Z wave and zigbee are “mesh” protocols where one device can pass along a message from another in a sort of Relay setup. So you aren’t limited to just the distance of one hop.
The FAQ linked to above explains more about that and describes how to apply it to device placement in a large house. 