I didn't see this anywhere - although I might have missed it. If you are relocating, make sure your indoor and outdoor storage has enough storage left for items you currently have placed. I would suggest if possible emptying your storages completely (place those housing items on a retainer or in your chocobo bag or inventory). You won't be able to relocate if the number of items currently placed in your house and yard exceeds the amount of room in your storages - I found that out when a dream plot came open a while ago, luckily I had time to run home, empty my storage and run back to relocate. Housing items placed in your house/yard are moved to your storage when you relocate, hence the need to make sure you have room in those storages so you can relocate quickly.