Existing knackered pipes come through trench in concrete floor, up to valves. Cannot run new pipes in trench for this radiator due to access to cut out trench being blocked upstream. So pipes will come out of trench elsewhere then run along bottom of the wall, plaster removed and clipped to the blockwork, to be hidden behind new skirtings eventually. Question is: how to get from behind skirtings to the radiator? I was thinking bend straight up in middle roughly and use plastic tails as though using speed fit outlet plates, except in the wall would be copper. Only problem is that would make the elbow higher than the radiator valves to get above the skirtings... possible air situation. I will probably move the radiator up a bit and maybe replace it with something nicer.
Along the wall at skiting height and up in the corner, through the ceiling and connect to upstairs heating circuit.