The link above won't give wifi in the lounge though - unless I missed the detail in the spec. They merely extend your wired LAN in a very convienent manner.
As TheEvilGiraffe asked, does your HH have to stay in the office. If so, due to the location of your master socket/phone extension then there may be another solution. Not sure of HH supports it but you can locate a second ap within the range of the existing coverage and it acts as a repeater. Never done it before myself and I think it cuts the throughput of your wireless by 1/2.
Suppose you could always use the BT power-line sockets and a second ap in bridge mode