Completely restricted rooms with no students allowed to enter. Principal of the Thing will scold the player when he sees them entering, exiting, or staying inside a faculty room.
One of the most common locations in the Schoolhouse. Some halls include standard doors and swinging doors to specific rooms. The Quarters can be randomly found in the halls.
The office owned by Principal of the Thing. This is where the player is sent for violating the school rules. This office is also the area where all school members' posters and descriptions can be viewed.
They are inaccessible in Classic and Birthday Bash. There is nothing interesting to find in these areas other than to serve as the outside world's decoration.
Schoolhouse map, made from the Schoolhouse's 3D model. Black numbers are character spawn points (1 - Baldi; 2 - Playtime; 3 - Arts and Crafters; 4 - Principal of the Thing; 5 - 1st Prize; 6 - Gotta Sweep).
Interactive map
Trivia
General
After collecting 7 notebooks in Story Mode, when the player walks up to a fake exit, an image of a map showing where the exit is will appear on the wall.
The Schoolhouse's map from outside while cheating.
If the player were to view the Schoolhouse from the outdoor areas (except the one with Baldi's Bus in Classic Remastered), the player can see through the walls. This is because the Schoolhouse is created out of walls that only have one side.
According to It's a Bully's poster description in the Principal's office and Bladder's second chalkboard, the Schoolhouse and the Super Schoolhouse are named as "here school".
mystman12 tried to make the classic Schoolhouse map in Minecraft, but it is not finished yet.[1]
But for now, it is unknown what happened to the map.
Baldi's Basics Classic/Birthday Bash
A full map in the 3D model program showing the invisible Arts and Crafters triggers.
When looking up the map's 3D model, there seems to be six hidden empty rooms in the map: two rooms between three hallways connected to the bottom right corner outside of the cafeteria, one around Gotta Sweep's closet, one from the hallway of the map's left-hand side where two connected faculty rooms are at, and two others from the hallway between where the pay phone is found. However, they are not actually rooms but instead the triggers for Arts and Crafters. What this means is that these triggers/boxes allow Arts and Crafters to show up in locations on the map.[2]
The reason why they show up is that they are actually collision boxes and are a part of the map, only that the renderer (the tool that allows boxes to be visible) is off, although the collision still exists.
Baldi's Basics Classic
The brightness of the Schoolhouse is different in some versions.
Prior to V1.3, the Schoolhouse used the default lighting for Unity games.
From V1.3 to V1.4.1d, it looked a bit darker than the previous and later versions.
Since V1.4.2 of Baldi's Basics Classic, it is brighter than the previous versions. The lighting in the versions is applied to the later games and demos (except for Field Trip demo).
Glitches
Baldi's Basics Classic/Birthday Bash
At the starting hallways, the carpet texture is sticking out of the "Spelling" classroom.
The original drawing of the Schoolhouse. The green-colored area was supposed to be a playground, but it was not implemented. It has 6 doors instead of 7.
References
↑"I actually tried recreating the original Baldi's Basics map in Minecraft once, but I didn't even get close to finishing it haha." - Gmail