Sadly, it's more than just sheet size. In waaaayyyy to many jurisdictions it's design by ordinance, not by what makes sense or is economically feasible. If it don't look like what the ordinance says it should, it's no go. In our county, we've gotten to the point where we have to submit 80% construction drawings, just to get planning approval, because that's the way the ordinance is interpreted.
In Oregon, all plats are to be filed on 18x24 w/ a 1" border (state law). Most civil plans are 24x36 and architectural 30x42 or 46. In California, all sheets MUST be wet stamped & signed. At least here, I can use a block of the seal, the boss can sign the originals, and photocopies made of those. Also, it says it has to be scale, but it doesn't say what scale. Sometime, just for grins, give 'em a project at 1:200 or 1:1000 & see what they say. 'Course, then there's the ACOE, and EPA which want their submissions on 8.5x11 for wetlands mitigation.
I've set my border up so that in 11x17 it's 1/2 scale. Leaves a bit more blank space in a 24x36, but not much. Works well & allot let fuss than trying to cram ever last bit into a 24x36.
Reid