Garage conversion gas pipe

[Pybara]

Hi, I am in the process of doing a garage conversion. There is a gas meter on the inner side wall of the garage with the gas pipe going straight down into the ground.

The pipe must lead out of the garage but don't know where. It is likely it goes straight out either under the side wall or under the garage door.

I am worried about removing the garage door to replace with a wall - will need digging for the foundations (probably 400mm) in case there is a gas pipe there.
There's a chance the gas pipe doesn't cross there and goes under the hallway or along the garage wall.

Any idea what to do in this scenario?

Is there any alternative to moving the gas meter outside (which could be costly)?
The ways I can think of are:
Can I dig carefully (e.g. without machinery)
Can I put an insulated replacement to the existing garage door that meets building regulations, is there such a thing
Can I determine location of gas pipe using metal detector

Some pictures show the scenario. Ideally the gas pipe is running under the side wall or side pillar but I am not sure of this

Thanks!

 

[^woody^]

The pipe would normally go out under the door in a straight line out to the main on the public foot path.

You can't build over a gas pipe.

 

[cdbe]

I think you're ok with steel, it's the plastic you can't build over (it melts in a fire and there's no way for the FB to isolate it). And yours is already "built over", you'll either have to fork out for a move or get creative with your boxing in/cupboard.

 

[bsr]

To detect where the pipe is you can hire and cat and Genny. You clip the Genny to the pipe and it makes the pipe emit RF. You then swing the cat back and forth and it beeps when over the pipe.