The common house was created to house transient wastelanders and potential citizens. All residents of the common house are under inspection from Lucas Simms and most, if not all, are saving up to buy a house. They are not considered to be Megaton citizens and are generally treated as outsiders by the main population of Megaton. Most residents of the common house work in Megaton in one function or another and receive rations of food and water.
On the first floor, three single beds and two bunk beds are placed along the east and west walls, with two lockers set up against the far wall. A footlocker and several tables and chairs are placed around the room. During all hours of the day, various Megaton settlers can be found on this floor eating meals, chatting about local gossip and sleeping in the beds. To the right of the entrance, a stair leads to the second floor. At the foot of the stairs stands a shelf with a box of Sugar Bombs on its lowest rack.
The second floor features a rectangular atrium in the center of the room with railed gangways running along either side. Dining tables, a park bench and a shelf populate the gangways, which look down upon the first floor. After arriving at the top of the stairs, the player will find a refrigerator directly in front of them and the stairs to the third floor directly behind. Settlers can occasionally be found milling about on the second floor, eating meals or sitting silently along the gangways. To the side of the stairs is a door which opens upon a small single bedroom with a chair, footlocker and shelf. Often a settler can be found sleeping or sitting in this room eating a meal.
On the uppermost floor, the player is met by a small pile of overturned tables, chairs and empty bed frames. A couch runs along the north wall and a table and two chairs are set up against the back wall of the room. Settlers rarely if ever visit the third floor of the common house.