The height of the Sukkah--as measured from the floor up to the sechach--may not exceed twenty amos [approx. 30 feet] and may not be less than ten tefachim [approx. 32 inches]. If the sukkah exceeds the former or is less than the latter, it is unfit for use.
The minimum length of a sukkah is seven tefachim, as is the minimum width. If either the length or width is less than seven tefachim, the sukkah is unfit for use.
The maximum measurements apply only to the height of the sukkah; as regards width or length, there is no maximum and any width or length - over seven tefachim - is fit for use, provided that one places a sufficient amount of sechach on the roof. Our Sages said: "All Israel are worthy of dwelling in a single sukkah." And, it is said, in the Time to Come, G-d will make a sukkah from the hide of the leviathan and all the righteous people who have kept the mitzvah of sukkah will be seated in it.
It is proper for a person to make the effort to build the sukkah personally.
If one is not well versed in the laws pertaining to the construction of a sukkah, it is fitting that he show his sukkah to a scholar while it is yet day so that he can make any necessary changes before the beginning of the Festival.
The mitzvah can be fulfilled by dwelling in a borrowed sukkah. Thus, one who did not build his own sukkah can fulfill his obligation by using his friend's sukkah. One should not, however, fulfill his obligation in a stolen sukkah. Thus, one may not build his sukkah in a public domain, for he is considered to have stolen the publicly owned land on which the sukkah stands.
