The corridors in John Endecott Memorial Academy are trapped between two different eras, both of them antiquated. The walls of the building while having had restoration still match their original design from when the main school building was first constructed. The original wooden flooring of the corridors has worn away over the years and has since been replaced by new lacquered flooring that gets notoriously slippery when wet. The corridors themselves run around the outside edge of the original school building with the entrance to the classrooms being located on the interior side of the corridors themselves. Stairs to the first floor can be found at the back of the building while the newer connecting corridors to the more modern wings are located opposite. Lockers line the walls of the corridors and there is a running joke among the student body that lockers are assigned at random due to the allocations following no discernable pattern. One block of lockers can be in use by all grades within the school.

The Endecott Cafeteria is located in the center of the ground floor of Endecott Memorial when the school was first constructed it was the joint largest room in the building—a trait it shared with the library. Over the years the interior of the cafeteria has been upgraded slightly but the original ceiling beams have remained in place. Eating in the cafeteria at John Endecott Memorial is a very communal experience as all tables are of a rectangle bench design and are arranged into three lines that span the length of the room. The food served in Endecott Cafeteria is considered passable but with the daily meal options being considered pedestrian many students prefer to bring their own lunches. There are also no vending machines in the cafeteria due to the only potential space for them being taken up by a set of stairs leading up into the memorial library, there is however a water machine available to one side of the counter.

The Memorial Library is located directly above Endecott Cafeteria and can be either be accessed from the first floor or in a strange piece of design from a set of stairs from the cafeteria. This causes a lot of student foot traffic through the library following lunch periods, much to the librarians' constant frustrations. Aside from this one piece of weirdness, the design of the library is in keeping with John Endecott Memorial's original design and like many of the original building rooms, it is known for its ability to get extremely hot and lack of air conditioning. Polished wooden bookshelves take up three-quarters of the room while the other quarter contains a collection of tables and chairs for students to sit and study. The library is open to all students throughout the week with the exception of Friday's where the use of the study space is reserved for the Seniors only, a practice that has been observed within the school since its founding.