Stackable Washer / Dryer Upstairs

I'm on the second floor of a condo that has very limited storage space, so I'd like to sell my washer and dryer and replace them with a full size stackable front loading unit. The condo complex isn't known for being well constructed, so my concern is if I have the washer and dryer both completely full, am I going to end up giving my downstairs neighbors a new washer, dryer, and skylight?