The passuk teaches us that one must fix the words of the Torah on the “doorposts of your house and your gates.” The questions arises, is there a minimum measurement to a room that requires a mezuzah? The Gemara in Sukkah learns out from the word “house” that the room must be large enough to live in, which Chaza”l determine to be at least 4 cubits by 4 cubits. This translates in our measurements to be between 6 – 8 feet by 6-8 feet.
Rabbi Aharon Dovid Singer
Rosh Kollel, NMB Kollel