Older thread but glad someone else has had this idea.
I was finding it such a chore when moving my layout around to move one building a couple squares, then move another, then move 3 pieces of road, then move the buildings again, then move two more pieces of road, then move the.... you get the point.
It'd be incredibly handy to have a garage where you can store a handful of things, even if it was for a limited time, while rearranging stuff for a more productive layout.
Even if it meant halting production on said building while it's in storage, say if it was a residence then it would stop producing gold while it was in storage, it'd still be handy a function.
EDIT: I don't mean a new building either that would take up space... I mean a simple function that you can click on a building, and bring up the window, and click a button that says something like "store" or something... and the building disappears... then you can open the store, select the building you want and put it back on the island.
One function that could be put in place to discourage people from abusing the function, if a building has been in the store for more than, say, an hour, or 2 hours, then your gold levels will drop by X amount every hour you store the building.
As others have pointed out by putting culture buildings on the island when they want more gold or something, then a time limit on storage with a penalty with an hourly gold payment would discourage abuse.