3 - If your entrance to your house has a metal door followed by a small hallway ( less than 4 x 4 Amot ) than the main door to your house. Which door should get the Mezuzah, or both ?
Thank You, for your help in advance,
Shmuel Katz
Logic would seem to dictate that the two doors comprise a single entranceway, and only one Mezuzah is required, on the outer door.
However, Rav Nisim Karelitz asserts that if the space between the two doors is more than four Tefachim, the inner door can be considered a separate door, bounding a "small" room of four Tefachim by four Tefachim. (Walls bounding *less* than four Tefachim are not considered "Mechitzos," and therefore they are not considered to be bounding a separate little hall.)
Such a small room would normally not be Chayav bi'Mezuzah, since it is not four Amos by four Amos. However, there are Poskim who say that a Beis Sha'ar is obligated in Mezuzah even if it is less than four Amos by four Amos, since it is made to serve a different purpose than a room inside of a house. The same can be said about this small room, by the entranceway. Therefore, in such a case the Mezuzah is affixed without a Berachah.
M. Kornfeld, based on discussions with Rabbi Eliyahu Feldman