UOX3.org

If you take careful note of where the house shows up in preview just before you click to place it, and of where UOX3 actually places the house, you'll notice that it'll be a few tiles thrown off target in either X or Y direction (possibly depending on the position of your mouse cursor?).

Might have something to do with why it's so difficult to place houses sometimes, even though there APPEARS to be just enough space available.

The house display is as a result of the MultiPlacementView packet we send to the client, it's estimating where the house would wind up as we move the cursor around. The house itself is centered on the exact X and Y you click on.

I'm not sure there's much we can do, aside from arbitrarily placing the house at a different location which seems to be the same as where the "ghost" image displays.