Hi there, I'm new to this forum and hope someone can give me a bit of
advice.

My gas meter is fixed to my external house wall but within a lean-to
garage. It is not recessed into the wall, it is mounted on a steel
plate fixed directly to the brickwork at a height of 1800mm. The
incoming gas pipe comes vertically from the floor to the same height as
the top of the meter but 200mm to the right of it and connects into the
top of the meter with a 'bendy' metal pipe. The cut-off lever is at the
top of the rigid vertical pipe. The outgoing pipe comes from the top of
the meter and bends left after about 600mm then runs along the garage
wall and into the kitchen wall further along.

I want to have the garage dismantled which would leave the exposed
meter outside.

I obviously want to box the meter in securely with a lockable door for
access (I assume this is legally necessary too?).

Now, most boxes I have seen for sale online assume the incoming pipe
comes in from below and the outgoing pipe goes straight into the
brickwork rather than back out of the box. Is it possible to buy boxes
that simply slot over full meters and bolt to the wall, with a means of
cutting out holes where the piping needs to go?

Alternatively is it allowed to make your own slot-over box? It would be
no problem for me to make a secure, weather-proof, lockable wooden box
to fully enclose the meter, flexible pipe and cut-off lever which I
could fit without disturbing any of the pipework.

Or any other suggestions?

hope this makes sense, with apologies for not knowing the correct
jargon!!

cheers
Alan