Corbeau

Thanks for the replies, folks. Yes, the condensation is on the inside of the windows. I'll suggest to them that they run the furnace's fan full-time to circulate the air a little more. I hadn't thought about the extra humidity caused by taping, paint and (probably) the cement floor downstairs in the basement. Speaking of which, how long should I wait before painting that basement floor?

In the brand-new (as in just-built-by-the-builder kind of brand new) house we just bought as an investment, I have condensation in the windows... Now, the nights are getting chilly (lows in the 40s) and my tenants (he's 87, she's 82) are probably cranking the furnace way up. Is that what would cause condensation to form in the windows? How shall I fix that?