Just as in Trading Spaces, two families trade homes for two days with no interaction during that time - it's all a surprise.  The twist in Trading Spaces: Boys vs. Girls is that a boy and a girl, each aided by a friend, get to redesign each other's bedrooms based on a "theme" supplied by the bedroom's occupant.  Unlike the adult version, there is no budget, which leads to rooms that tend to be more "over the top", often in the neighborhood of $5,000!   The one caveat: NO PARENTS ALLOWED!