Q. I learned that if someone buys a house that is already painted, he does not have to remove the paint of a square amah, as a zecher lechurban (Remembrance of the Destruction of the Bais Hamikdosh). Should he at least place a painting, picture or any other remainder instead?
A. After the Churban Beis Hamikdosh our Sages instituted that one should demonstrate or exhibit a Zecher Lechurban at every joyous occasion in one’s life. One application of this Halachah is that when building or renovating a house or apartment, one should leave an unfinished area measuring a square amah, (approx. 58 cm. square following Chazon Ish opinion or 48cm. square according to Horav Chaim Noeh) which can be seen right away when one enters the house. (Bava Basra 60b)
Shulchan Aruch (O.H. 560: 1) indeed rules that if one acquired a house that is already painted, one does not have to remove the existing paint. However Mishna Berura (ibid. 4) cautions that the above applies only when the house was the property of a Gentile. Otherwise, since the Jewish prior owner was already obligated to leave a Zecher Lechurban, the new buyer should comply and remove the paint.
Horav Shlomo Miller’s Shlit’a opinion is that when the painted house was purchased from a Gentile, although there is no obligation to create a Zecher Lechurban, it is commendable to do so, and it suffices with a painting, picture or any other remainder.
Rabbi A. Bartfeld as advised by Horav Shlomo Miller Shlit’a