"Today's photograph illustrates a design feature common to many occupancies including motels, hotels, condominiums, offices, retail shops and apartments: the exterior egress balcony. In this design, the dwelling or tenant space opens onto an open-air means of egress that provides two or more options leading to an exit. Since an exterior egress balcony is essentially a three-sided corridor (floor, ceiling and one wall), it must meet the same construction requirements as corridors for width, headroom, dead-ends and projections."
Coffee Break Training - Fire Protection Series No. FP-2009-42
United States Fire Administration: http://www.usfa.fema.gov/