A foldable building structure is provided that includes a fixed space portion including a first floor portion, a first ceiling portion, and a first wall portion. The structure includes a second ceiling portion and a third ceiling portion each movable between a folded position that is proximate to the fixed space portion and a deployed position. The second and third ceiling portions are movable from their respective folded positions to their respective deployed positions to form with the first ceiling portion a ceiling component of the building structure when in their deployed positions, the ceiling component having a periphery. At least one of the first floor portion, the first ceiling portion, the second ceiling portion, or the third ceiling portion includes at least a section of a closed-loop passageway proximate to the periphery in the interior portion adapted to contain a utility line.