Elmer fixes up a room for his just-married, freeloading brother-in-law and wife. When the newlyweds show up, Henry brings a surprise in the form of stepson Junior. The apartment is now too small, so Henry decides that they'll buy a lot and build a do-it-yourself home, a disaster in the making when Junior switches the house's part numbers. It doesn't help matters that Elmer, Henry and the wives are all incompetent.

Once again finding themselves out of work, Karl and George get a job assembling pre-fab houses -- with disastrous results.