Location Requirements
IRC 2000	Handrails required on at least one side of ramps exceeding a slope of 1:12.   Handrail required on at least one side of stairway
IRC 2001	Handrail required on at least one side of stairway with two or more risers.
IRC 2003	Handrails shall be provided on at least one side of each continuous run of   treads or flight with four or more risers.
IBC 2000	Handrails required on both sides of stairs and ramps.
IBC 2001	Amended to add the following:  Aisle stairs complying with Section 1008   provided with a center handrail need not have additional handrails.
IBC 2003	1009.11 Handrails. Stairways shall have handrails on each side. Handrails   shall be adequate in strength and attachment in accordance with Section   1607.7. Handrails for ramps, where required by Section 1010.8, shall comply   with this section.        Exceptions:                  1. Aisle stairs complying with Section 1024 provided with a center                 handrail need not have additional handrails.                  2. Stairways within dwelling units, spiral stairways and aisle stairs                 serving seating only on one side are permitted to have a handrail                 on one side only.                  3. Decks, patios and walkways that have a single change in                 elevation where the landing depth on each side of the change of                 elevation is greater than what is required for a landing do not                 require handrails.                  4. In Group R-3 occupancies, a change in elevation consisting of a                 single riser at an entrance or egress door does not require handrails.                  5. Changes in room elevations of only one riser within dwelling                 units and sleeping units in Group R-2 and R-3 occupancies do not                 require handrails.
ANSI A117.1	Handrails required on both sides of stairs and ramps. EXCEPTION: Aisle stairs and aisle ramps provided with a handrail either at the side or within the aisle width.
ADAAG	Ramps - both sides, if rise exceeds 6 inches or a horizontal length more than 72 inches. Not required next to seating in assembly areas. Stairs - both sides.
Intermediate Handrail Requirements