The only issue here is whether the estate had gross income of at least $600.  Sale of real estate often results in zero gross income, or a loss, when its value has not increased since date of death.  So you haven't told us enough to answer your question.  Does the estate have any other income?  And, since the loss on the sale of the house (due to closing costs) would pass through to the beneficiary, it might help him to file a return and issue a final Schedule K-1 even if not required.