The man had wanted to surprise his partner by descending in front of her bedroom in the town of IJsselstein to sing her a song and pop the question.
But the unsecured crane he used instead toppled into a neighbour's house.
The woman still said yes, Dutch media report, and the couple are now said to be celebrating in Paris.
Following the initial impact, more damage was done when the crane fell again during an attempt to right it, the BBC reported.