Because the ht of the door is measured from the top of the curb, you get an extra 4" of ht. An 80" door will top out around 84" from the floor, which is probably more ht than would be necessary from a functional perspective. Your question balances between what is esthetically pleasing to your eye and what will provide enough ventilation to eliminate the fungaluglies (mold/ mildew) as a perpetual issue. You can't have too much ventilation.

Al

Thank you. We're doing a curbless and doorless shower. I feel like I'm pretty certain we're going to have the glass panels go up to 84" (7 feet). That way they should be at about the same height as the casing around the door frame.

..... sound reasoning. Whenever it works out, we try to match the ht of the shower partition so it appears as a continuation of an existing horizontal line. Most often that line would be something like you mentioned - the top of trim around a door/window, top of nearby cabinetry or mirror, or even just a grout line - something to make the ht look planned, rather than something random or 'made to fit'.

Good luck - Happy New Year.

Al