Q. Does an elevator that measures more than six by six feet and services a condo building were all or most of the owners are Jewish require a mezuza?
A. Maseches Mezuza (2: 4) quotes a disagreement between Beis Shamai and Beis Hilel if a door that requires a movable ladder to enter it, requires a mezuza, Beis Hilel is lenient.
Poskim present three different opinion in regard to an elevator. 1) Chovas Haddor (5: 11) considers an elevator as a regular staircase that connects all floors, and is therefore liable to mezuza. On the main floor that has street access, he rules to place the mezuza on the right side of the door one enters the elevator. On the other floors, it should be on the right side of the person entering that floor from the elevator. It seems from his wording that a brocho is recited.
2) Be’eir Moshe (2: 88-90) maintains it is totally exempt, since the elevator moves from floor to floor, and it is not designed as a habitation unit. See also Betzel Hachochma (3: 80).
3) Minchas Yitzchok (4: 93) rules to install a mezuza without a brocho only on the door inside the elevator itself, since although it is not designed as a habitation unit, it serves an essential purpose and need for the dwellers. Therefore, even if it does not measure 4 x4 amos, it should have a mezuza.
However, the elevator doors on the building itself are exempt, as there are of no connecting use when the elevator is not on their floor.
Horav Shlomo Miller’s Shlit’a opinion is similar to the Be’eir Moshe, since an elevator is considered as a movable ladder, and no mezuza is needed. That is indeed the common minhag.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a