We have a factory project with some rooms where I am not sure about their classification as "occupiable" or not. Specifically they are "dirt removal" and "cleaning" rooms. I am still working out the actual type of activity that will occur in these rooms, but I still want to ask the question because I'm having trouble understanding how in practice a room is defined as "occupiable" or not. I have seen in other posts and in ASHRAE 62.1 the definition: "an enclosed space intended for human activities, excluding those spaces intended primarily for other purposes, such as storage rooms and equipment rooms, that are only occupied occasionally and for short periods of time."

I have never had to demonstrate the fresh air supply in Toilets (restrooms) in my LEED submissions, and I see most discussion about toilets on this forum are related to exhaust rates. So am I right to say that Toilets are not considered "occupiable"? We have never included toilets in our ASHRAE 62.1 fresh air calculation and never had a comment about it.

But why would toilets not be considered occupiable but corridors and vestibules be considered occupiable? I saw a comment that a LEED reviewer will usually consider that if the time spent in the room is less than 15mins it would be considered a "short period of time". But I think it could be argued that corridors and vestibules are "occasionally" occupied and in most cases certainly for "short periods of time". A toilet has more of a human activity purpose than these types of spaces. The only explanation I can think of is that ASHRAE included "corridor" as one of its occupancy categories, but at the same time "storage" and "electrical equipment room" are also ASHRAE occupancy categories even though they are specifically mentioned as excluded by the "occupiable" definition as above. Does anybody have further insight about this?