OUr gas meter is at high level in the pantry of our bungalow. There
is an airbrick at about 4' height which introduces quite a lot of cold
air and dust/dirt and SWIMBO would like to block it off.

Google isn't clear. What and where are the regs applying to it and
more simply can I put a piece of card in front of the airbrick?

--
AnthonyL