Where is the condensation? on windows? door knobs? If windows you can probably better insulated windows if they're so anal about it (the kind with 2+ layers of glass with a vacuum between them). I'm not sure if it may work but maybe you can try to find some anti-fog spray or coating for the windows that way the condensation may be less prone to stick.. dunno if that would work but worth a shot.
If its on the doorknobs i dunno what you can really do except maybe get a plastic handle or maybe rubber coating or maybe have knit a little sock for the knob.
But yea there's gotta be a something going on.. maybe they take extra hot showers or something and the bathroom needs a fan/vent. Maybe the dishwasher (if there is one) is the culprit. Maybe the toilet is using hot water instead of cold. Could be anything, really.
Edit: I'm kinda tired and bored and just spewing that stuff out of my ass. But maybe some of it can be useful,.. I've been told on many occasions that i have a smart ass.
