67. Structures That Might Not Require a Mezuzah

11:14 A house that is not built for permanent residence, such as a succah or a stall in a flea market, does not require a mezuzah. A store that permanently houses merchandise, however, does require a mezuzah.

A porch that has three walls and a ceiling but that is open on the fourth side does not require a mezuzah even if it has two pillars set up like a doorway. In such a case, these pillars are not placed there as doorposts, but rather to support the roof. If the porch does have a wall on the fourth side, even if it wall is so low that it does not reach the ceiling, it does require a mezuzah.