. Where in two sides of corridor there is wall edge, then the clearance width must be in accordance with regulation in clause . . Handrails in two sides of corridor must be at an elevation of 900mm. Rotating angle at deviation points is preferably arched wall face or right angled wall face. Where there is difference in elevation at the extremity of corridor and the end of corridor with floor surface or ground surface, it must be balustrade, shielding plate or shielding edge, and there is a need for installation of safety signpost. .