The Lightwave Link and Link Plus have generally excellent penetrative wireless range which should out perform alternative WiFi / Zigbee / Zwave standards. One link should comfortably serve a large house and garden.
In areas where devices are not reliably receiving commands from the App/link, the wireless signal may not be strong enough to reach them. A maximum distance of 15m between link and device is recommended, but large bodies of water or metal may interfere with the signal to reduce this distance.
Try to make sure that large metal objects such as radiators or water tanks are not placed in the path of the wireless signal. Situating the link as high up as possible within the building (i.e. top floor) also helps to improve the range.
Also note that Generation 1 relays and power sockets require a minimum separation distance of 30cm, and they should not be situated in metal casings that could interfere with transmissions.
For larger areas requiring greater coverage 2 Links (Gen1) can be used in combination to extend wireless range. Currently it is not possible to have 2x Link Pluses under the same account to boost the range.