Thanks for the advice, I'll arrange some visits for quotes as sounds like there are a lot more factors to consider that my zero knowledge of pipes and plumbing understands.
Gentlemen,
Looking to have a radiator moved round the corner of the room roughly 10 feet away from where it currently sits to allow knock through from lounge to kitchen. House is a 6 year old new build, lots of cardboard hollow walls(!), radiator has a wall plate so no piping is under floor...