â€Isn’t it enough to have a Mezuzah on my front door?â€
”Isn’t it enough to have a Mezuzah on my front door?”
It's a common misconception that it is sufficient to have a mezuzah on the front door of the house, or perhaps that this mezuzah is somehow more important than the mezuzos inside the house. In fact, the halachah is that all doorways of a house that lead to rooms occupied by people or used for storage require a mezuzah.
A bathroom is an exception, since it's not a diras kavod (respectable living quarters). The “leniency” of a single-mezuzah home harks back to a time of other modes of living, and certainly does not apply to modern buildings (with indoor plumbing, yet).
The outside door of a home is actually sometimes less likely to need a mezuzah min HaTorah (according to the Written Law), since it often leads into a foyer—which is considered merely a bais shaar (an entranceway) into the home, and not an area of residence. According to some poskim, a bais shaar needs a mezuzah only mi’d’rabbanan (by Rabbinic decree).
The foyer is often smaller than the requisite dimensions for a mezuzah, according to most poskim. A room needs to be at least four by four amos (arm lengths, i.e. approximately six feet in length and width) to require a mezuzah.
Any small room that is the same overall size as a room of four by four amos (an area of about thirty-six square feet), even with different dimensions, doesn't require a mezuzah, according to some opinions; therefore, when affixing a mezuzah, no brachah may be recited. Some maintain that a bais shaar requires a mezuzah even if it is less than the requisite dimensions, but likewise, no brachah is recited. (The only pass-through that all agree does not require a mezuzah, is an area less than four by four tefachim—approximately one square foot.) Accordingly, when homeowners recite the brachah on affixing mezuzos, they should choose the mezuzah of a larger room— ideally one with an actual door—upon which to make the brachah.
A room with multiple entrances requires a mezuzah on each doorway, and each is a mitzvah onto itself. A house where even one room is occupied requires a mezuzah—on the doorway(s) of the room being resided in, as well as all doorways of pass-through rooms on the way in and out.
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