The school is shown as a multi-story building but in one episode a rounded skylight is shown and in all episodes they always stay on the ground floor.
When Lisa reveals that she is Jake Boyman (A.K.A. Toilet), Bart is seen being shocked like everyone else in the audience even though he already knew that.
After two girls entered the girls entrance of the school, Lisa suddenly appears.
From the front, the school is divided into the girl's pink half on the right, and the boy's blue half on the left. Yet in a scene that shows the exterior of the school followed by an interior shot, the girl's school, apparently, continues off to the left. Geographically, this should be part of the boy's school.