Q. If the house I own does not have enough space over an inside second entrance door to leave a full amah by amah zecher lechurban square, can the amah by amah required be rectangular instead, having exactly the same area?
A. Poskim disagree. Pri Megodim (560: M.Z. 1), Shaarei Teshuva (ibid.) rules that it should be a square. However, other Poskim maintain that an area of a square amah is sufficient even if one side is less than an amah (e.g. 2 x ½ amos, which is an area of a square amah – Horav Yisroel Belsky, Piskei Halochos, 1: p. 113, quoting Sefer Habayis, p. 215: ft. 11).
Horav Shlomo Miller’s Shlit’a opinion is that in need one can be lenient.
Rabbi A. Bartfeld as advised by Horav Shlomo Miller Shlit’a