You'll need 3 relocations if you want to switch houses around. You move one house to an empty plot temporarily, then you move your second house to the first plot, then you move the house in the temporary plot back to the second houses original plot.
I do wish however they added a switch option so you wouldn't need to do it like this.
Instead of putting a restriction or "lockout" on relocation, I rather see it being a reportable offence if people are relocating just to harass/mess with other players.
