Just to make sure.......

[Doomed]

Block of flats having gas meters installed all in one location (a fair distance from MET).
Its OK to have one earth bond chaining them together as long as the earth is unbroken isn't it?
Therefore allowing one length of neat conduit running around exterior.

 

[Pete999]

Seems you are correct

 

[Leesparkykent]

Is there a switch room/mains room with the meters in?

 

[Doomed]

Mains room with the 3 phase incomer and MET, new gas meters external on another edge of the block of flats.

 

[telectrix]

Mains room with the 3 phase incomer and MET, new gas meters external on another edge of the block of flats.

sod the meters. bond to within 600mm of the pipes entry into the building. it's only gas monkeys that want to bond to external meters.

 

[Leesparkykent]

What size is the incomer? You might have a hell of job sizing a bonding conductor and it being suitable to loop across the gas services.