I'm a bit surprised by this as well since I do Set Decoration and I too would never lend out my abode. I had a Costume Designer recetnly offer up her house to production and then have as much shock as in your case when too many people were in the house and moving stuff.The only reasoning I can come up with is that the Set Decorator is rarely on set, they are usually working on the next set so they may have forgotten about the logistics of being on a functioning set. I guarantee, you will never see an on-set dresser offer up their home. They know better.As for the Costume Designer I think she was told it would be a quick couple set-ups but of course it wasn't and because she spends most of her time with clothing in the wardrobe room/office I think she also didn't realize the damage that would/could be caused.