Thanks, I'll get him to go for the rewire, it is well overdue, and if
he's bothered about too much mess I'll use conduit on the surface. Each
bedroom only has one socket at the moment anyhoo, so by adding another
per room wont be much bother.

Legally, you will need to add a lot more than one per room. There are
minimum standards for the numbers of sockets in each room. This is to
improve safety by reducing the use of trailing leads (trip hazard) and daisy
chained adapters (electrical and fire hazard).

Christian.