New HEP2O Heating between additional insulation and plasterboard - Insulation question

[Colink]

I am not a plumber so feel free to tell me if I am incorrect in anytingng I describe or ask.

 

My son is adding additional internal 50mm foil backed insulation to all internal walls of his 1890's timberframe hosue + a vapour barrier. Insulation supplier has calcculated minimal consensation risk to existing vapour barrier.

 

He will also be completely replacing the whole the heating system - either Oil Boiler or Air Source Heat Pump (grant ddependent) + new radiators.

 

He plans to add HEP2O below the bottom horizontal battern before adding plasterboard and plaster. - see attached image

 

I would appreciate a comments on what insulation, if any should be applied to the HEP2O pipes.

 

He is already losing some room space and keen to make battens as thin as possible.

 

Would minimal insulation wrap around the pipes plus insulation above the pipes (below the batten) be sufficient?

[JohnMo]

If you go on heat geek, they don't bother insulting pipes within the heated envelope, as heat is not wasted. Only exception is hot water cylinder heating pipes, as these would add to summer heating, so should be insulated.