Las,
The above I mentioned I think is לקוטי יהודה in the name of the אמת אמרי.
“the house belonged to the monarch”
That is another answer and some question that too, as Mored be’Malchus assets belonging to the king may only pertains to Malchei Yisrael and not to Non-Jewish kings. See below link Rashba that says its not so simple (4th line)
http://www.hebrewbooks.org/pdfpager.aspx?req=1376&st=&pgnum=398&hilite=
I think in sefer Hamitzvos RS”G of Rav Perlo has a lengthy discussion on that matter of the house…