i have recently had a new cetral heating system fitted and there is copper piping inthe hallway, and walk in cupboards not boxed off is this legal?

Of course its legal,if you dont like the look of the pipes its down to you to have them boxed in not your plumber.If its a job you dont feel confident in doing yourself post it on here in the correct section & get someone round to do it for you.In 25 years in the trade i have never known a plumber box his/her own pipes in.

mw correct ,if you want pipes boxing in ,or the other 1 we hear a lot on here is chases the sparky makes when rewiring ,these trades run their pipework/cables the best route possible ,it up to you or the building contractor if he has priced or if you are willing to pay to cosmetically modify these after