This is a fascinating question from the perspective of applying classical halachot to new situations, which leads to varied conclusions in this case. As far as the bottom line l’maaseh is concerned, our response will be somewhat straightforward. We will refer to a residential building. The status of mezuzot in commercial settings, even in normal rooms, is a major discussion in its own right.[1]
The Rambam[2] says that there is no need for a mezuza in a sukka or in a house on a boat because these are not permanent places of living. One can similarly claim that an elevator is not part of a permanent place of living. Although access to the elevator is an extension of the use of a building’s apartments, which are permanent abodes, from the perspective of any specific apartment or floor, one cannot enter the elevator whenever he wants. Rather, the elevator is available to any given housing unit only at certain nonspecific times.[3]
On the other hand, the Shulchan Aruch writes that a beit sha’ar (a hut that serves as a gateway) that opens into a house does require a mezuza.[4] This is true even when the beit sha’ar does not have the regular features of a room that ordinarily require a mezuza. Thus, for example, a beit sha’ar must have a mezuza even if its dimensions are not 4 amot (approximately 6 feet) by 4 amot.[5] In a sense, then, an elevator is more likely to require a mezuza than a sukka. As it moves up and down from floor to floor, it serves a function on behalf of people who live in the building on a permanent basis.[6]
However, this is far from a simple matter. First, the view that an area can require a mezuza just because it serves another area that requires one is not necessarily accepted.[7] Second, the elevator does not serve as a fixed beit sha’ar for any given floor, but is rather a moving beit sha’ar.
There are a variety of opinions among contemporary poskim regarding whether one should put a mezuza by an elevator.[8] Those who do recommend placing one for the most part instruct to do so without a beracha because of the doubt regarding whether it is really required. These poskim must also contend with another issue – where one should put the mezuza. On the one hand, there is logic to putting it in the entrance from the corridor into the elevator shaft. This would require a mezuza on each flight. One posek rules that on the ground floor, where one enters the building, the mezuza should be on the right side going into the elevator. In contrast, on other floors, where one presumably first arrives by exiting the elevator, the mezuza should be on the right side from the perspective of one leaving the elevator (i.e., the left side when facing the elevator).[9] On the other hand, some claim that since the elevator shaft is just a dangerous empty space that is sealed except when the elevator door opens, one should put a mezuza only on the right side of the entrance of the elevator itself. That way, whenever one would move from the corridor to the elevator shaft, one would meet the at the elevator’s entrance.[10]
At any rate, what is most important to us in this case is that the minhag ha’olam[11] is not to put a mezuza anywhere around an elevator. While we have seen some reasons why one might want to do so, we have not found close to a consensus of poskim who require it. Faced with such uncertainty, it is better not to start a trend that challenges an accepted practice. We prefer not to encourage the not uncommon phenomenon in our days of a chumra[12] race – in this case, to have a “halachically mehadrin” building. In many circles, this could be perceived as casting aspersions on the masses, and the drawbacks of the chumra would thereby outweigh its advantages.