How can I hang down the Christmas wreath (about 1kg bulk ) on the PVC front door? ...

Feng shui for relationships?
Answers:    Try using a wreath hanger that can be placed right over the door itself and no attachment is necessary. This can be used over and over again! God Luck!!!
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The over the door hanger might work, depending on how much room here is on the top of the door.
But you could try those new hooks by 3m that you attach and they verbs off when you're done beside them and leave no residue...they seem to be to hold a good amount of mass.