It is not allowed in any stairwells, doorways, or entrances to buildings. The impact severed all the elevators and all three stairwells. The standard uses American units and applies to pedestrian queues, walkways, and stairwells. Istana Nurul Iman has 564 chandeliers, 51,000 light bulbs, 44 stairwells and 18 elevators. The workers reported that the stairwells and elevator shafts were collapsed. The core contains elevator shafts, emergency stairwells and service conduits. Furthermore, the walkways and especially the stairwells could not be seen by anyone elsewhere. Skylights bring sunlight into the open stairwells. The two stairwells were constructed of dressed limestone walls. Each building has 3 floors and includes an elevator and 2 stairwells. Fire suppression design features included pressurised stairwells, smoke venting and fire retardant floor barriers. There was no foyer connecting the two stairwells. Several buildings were closed temporarily because of doubts about stairwells. It plows to the building's core, severing all three gypsum-encased stairwells, dragging combustibles with it. When he ran out of hiding places he slept in apartment house stairwells.