This thread was originally posted in the other place, and is a team effort to collect together as many acronyms and abbreviations used in the building trade as we could. If you know of any abbreviations missing, or think there should be a correction to the list, then post them as a reply to this topic and one of the moderators can edit the original list to keep it all up together.   AAV = Air Admittance Valve. (Sometimes referred to as a Durgo Valve.) AAV (alternative) = Automat