Lovely Thank you for your help!
Extract from the BT WiFi disc FAQ:
Your first disc will use the Ethernet port to connect to your hub (router). On the other discs you can use the Ethernet port to connect other wired devices to the network.
Thanks all for your help.
So it looks like if I want to connect multiple devices in the Garden Room I will need to connect the Home hub disc at the back of the house to a wireless router or access point in Garden room via Ethernet cable.
Although confused which one I need Router or Access point and it looks like that will need to be on Different SSID to the Home Hub.
A router is not needed, but a surplus router can be repurposed as an access point.
Entirely up to you if you set a different SSID, but I recommend that you do so that you are aware of which device you are connecting to.
@licquorice Perfect so I need an Access point.
I presumed would need different SSID as would muck up the mesh!
Presumably this will do the Job?
TP-Link 300 Mbps Wireless N Access Point, Passive PoE Power Injector, 10/100M Ethernet Port (TL-WA801N)
Yes, but please delete the link. It is against forum rules to post links to e-commerce sites.
Thank you all for your help! If the forum rules would allow me would buy you all drinks via PayPal! I'm sorry I'm such a newbie!