This Architectural Drawing is Working drawing of balcony and its railing. A balustrade is a railing supported by a series of balusters. Balustrades are sometimes short and ornamental parapets (low, protective walls) found on balconies and terraces. The national building code and Madhya Pradesh Bhoomi Vikas Adhiniyam specifies the height of a railing in a balcony, lobby or roof-top to be 1.05 metres (3.44 feet) from the floor-level. The word parapet (as mentioned in TypeIA's abswer) describes a wall-like structure that surrounds a balcony or roof. Another related term is Balustrade which refers to a series of pillars or poles supporting a handrail. Generally speaking, the balcony should be a minimum of 4 ft (depth) by 9 ft (length) so you ideally have enough room for a small table and the ability to maneuver around. For more details and information download the drawing file.
