In the episode "Father of the Year", Marcia climbs down the trellis from her bedroom, which is shown at the FRONT of the house (on the street side). However, in a later episode "Big Little Man", Bobby climbs up the ladder after Greg tells him not to. Greg pulls him over the windowsill into the girls' room, on the SIDE of the house. Not a big thing, but definitely a goof on the archictectural set up of the Brady house.