Building Codes & Standards

Understand IRC and OSHA requirements for safe stair construction.

International Residential Code (IRC)

The most widely adopted building code for residential construction in the United States.

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Maximum Riser Height

7.75 inches (196mm)

Critical

Minimum Tread Depth

10 inches (254mm)

Critical

Minimum Headroom

80 inches (2032mm)

Critical

Minimum Stair Width

36 inches (914mm)

Maximum Riser Variation

3/8 inch (9.5mm)

Critical

Handrail Height

34-38 inches (864-965mm)

Nosing Projection

0.75-1.25 inches (19-32mm)

Landing Depth

Minimum 36 inches (914mm)

OSHA Requirements (Commercial/Industrial)

Occupational Safety and Health Administration standards for workplace stairs.

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Riser Height Range

6-7.5 inches (152-191mm)

Critical

Tread Depth

Minimum 9.5 inches (241mm)

Critical

Stair Width

Minimum 22 inches (559mm)

Critical

Angle Range

30-50 degrees from horizontal

Safety Guidelines

Best practices for safe stair construction and use

Consistency is Key

All risers and treads in a flight of stairs must be uniform. Variations can cause trips and falls.

Handrails Required

Stairs with 4 or more risers require at least one handrail. Stairs wider than 44 inches need handrails on both sides.

Adequate Lighting

Ensure stairs are well-lit with switches at both top and bottom. Consider adding lighting to each step for safety.

Non-Slip Surfaces

Use non-slip materials for treads, especially for outdoor stairs or areas prone to moisture.

Additional Resources

Official sources for building codes and construction standards

International Code Council (ICC)OSHA Regulations NFPA Life Safety Code