sealed room 10 will be located a portion of the front wall 12 and the first sidewall 16 at the first front corner 20 are substantially thinner compared to the rest of the portion of the same walls the prefabricated sealed room 10 may be further divided into two portions namely a hallway portion and a room portion the hallway portion of the prefabricated sealed room 10 is defined by the partition wall 28 first sidewall 16 a portion of the front wall 12 near the first front corner 20 and a portion of the rear wall 14 near the first back corner 24 the hallway portion of the prefabricated sealed room 10 may include stairs 30 depending on where the prefabricated sealed room 10 is located the rest of the portion of the prefabricated sealed room 10 is termed as the room portion referring to fig1 through 4 the prefabricated sealed room 10 further comprises a first chamber 32 located at the second front corner 22 and a second chamber located on top of the first chamber 32 the first chamber 32 is defined by a second front corner portion of the floor slab front wall 12 and the second sidewall 18 and a portion of a first wall 34 that is parallel to the front wall 12 a portion of the second wall 36 that is parallel to the second sidewall 18 and an intermediate slab.