Jon,
Your RGI will be able to advice better on site.
Yes you could go through the wall into the ground, and come out of the ground on the outside of the outbuilding, provided the copper is large enough, which is unlikely.
30m of 32mm PE will give you 4.8 so will serve most combi's.
Yes you need local ISV's both ends.
The RGI would need to calculate the total load on the meter and arrange for it to be upsized, at the same time he would need to confirm with the supplier whether the service pipe is large enough.
Based on assumptions the copper pipe would need to be 35mm or larger.
It would be better if the new pipe could be taken back to the meter, but anything over 40m and you would be looking at 50mm pipe.
Whatever others may say on the subject, You need an RGI and possibly one with a commercial ticket for the outside work.
Your RGI will be able to advice better on site.
Yes you could go through the wall into the ground, and come out of the ground on the outside of the outbuilding, provided the copper is large enough, which is unlikely.
30m of 32mm PE will give you 4.8 so will serve most combi's.
Yes you need local ISV's both ends.
The RGI would need to calculate the total load on the meter and arrange for it to be upsized, at the same time he would need to confirm with the supplier whether the service pipe is large enough.
Based on assumptions the copper pipe would need to be 35mm or larger.
It would be better if the new pipe could be taken back to the meter, but anything over 40m and you would be looking at 50mm pipe.
Whatever others may say on the subject, You need an RGI and possibly one with a commercial ticket for the outside work.