I have edited this a bit to make it clearer. I really would like to know from someone out there whether there is a real regulatory issue here as I find the literature pretty impenetrable for the layman. I am concerned that my house insurance might be undermined and I am concerned about real problems in the case of a house fire!
I have plastic gas pipes laid under the house to supply a gas fire. These are sheathed in larger plastic pipes - which seems to be OK from a reg. point of view. These plastic pipes (painted to disguise them, I think) are connected by a steel connector (which is busily rusting) attached to the house at a metre above ground level to narrower copper gas pipes leading to the meter and the street supply.
I am being told that all of this is a no-no and that I must have the supply to the gas fire (on the opposite side of the house to the meter) re-piped in copper passed through the roofspace and the under-house pipes disconnected. Is this right? The house was diy built in the 90's.