Room 12a is the smallest room on the ground floor of Unit 5 (3.5 x 2.8 m). Due to its location within the unit and the absence of windows, it is designated as a bedroom.

The floor is covered with white mosaic, and the walls are adorned with wall paintings spanning three layers.

The first and oldest layer is decorated with red circles and red leaves on a white background. This painting appears to have been done quite hastily and carelessly.

A portion of the second layer can still be seen on the north wall. It displays a plain white background without any paintings.

The third and most recent layer is largely preserved on the north and south walls, clearly outlining the decoration scheme. A rectangular area displayed on a 60 cm marble base is adorned with imitation marble and crowned with a light brown and purple cornice.

However, the east wall has been damaged down to the base.