The answer seems to be “when it’s a sheet.”
The strangest little things irk me, and one of them is the use of the word “sheet” to refer to “drawing.” You encounter “sheet” everywhere in AE conversation and writing. Even the “Drawing List” on drawing cover pages is often titled “Sheet List.”
I confess that I’ve never heard of a problem arising out of the use of the word “sheet” on a construction project. I’m probably the only person that’s ever noticed it. I commented on this in a recent Northern Illinois CSI Specification Roundtable teleconference, and judging from the silence on the other end of the teleconference, the rest of the participants were decidedly underwhelmed by my concern.
But correct usage matters, especially in writing. My schoolteacher mother and my attorney father convinced me of that.
In a conversational setting it’s fine to refer to drawings as sheets, but formal AE project communication should use the term “drawings.”
Why? In AIA A201 – General Conditions of the Contract for Construction, the definition of the contract documents includes “drawings”, not “sheets.”
I just did a word search for “sheet” in A201. Result: zip. The word “sheet” doesn’t cut any mustard with the wordsmiths at the AIA . Searching for “drawing” resulted in many hits. I stopped counting somewhere in the twenties.
I rest my case.