Deeds can be resized by the mayor at the token or with the settlement deed. You cannot resize if the settlement is under siege. There are no refunds for downsizing. Premium time is not required to re-size a settlement.
The mayor can move expand his perimeter over a house which he do not have the writ for. This preserves as a warning for a deed expansion and gives the owner of the house time to move. Only the perimeter can be moved expanded over a house, the mayor has to have the writ to move expand the deed over the house.
The money needed to resizing must be either on the person resizing or in their bank.