Considering that Abraxas Malfoy was still alive when Lucius resided in the manor with his wife and son, and Draco likewise took over the ownership of it and lived there with his wife and son, while both Lucius and Narcissa were still alive, it is possible that the ownership of the Manor is passed on from parent to child when the latter in adult age is to marry and have a family of his/her own. If this is the case, the Malfoys have a presumably somewhat smaller property into which they move.