Thinking of buying a Victorian semi - haven't seen the struct survey yet
but says there is indications of rising damp in the party wall.

Be sure it is really damp. Surveyor's reports usually include the dampness
in the walls line. Frequently it is a bit like the Soviet era aviation
meteorology reports which always without fail said there was a 10%
probability of thunderstorms, even when the weather was excellent. No-one
wanted to get sent to a gulag if a freak storm hit.

If the plaster, paint and any wallpaper stays on the wall, I wouldn't worry
myself. If they are peeling, blown (or recently replaced), there may be a
problem. The damp readings were probably taken with a Heath Robinson
resistance meter that measures how hard you push more than the dampness.

Christian.