Building codes for mezzanine stairs vary by jurisdiction. Mezzanines may require multiple sets of stairs for safety, depending on the specific requirements of the building code and the intended use of the mezzanine.

According to the International Building Code (IBC), mezzanines that are more than 30 inches above the floor level below require at least two means of egress, one of which must be a stairway. This means that there must be two separate sets of stairs leading to the mezzanine: one primary stairway and one secondary stairway as an emergency exit.

Additionally, the IBC also requires that the width of the stairs and landings must be at least 36 inches, and that the stairs must be enclosed with walls or guardrails.

It is important to work with a knowledgeable contractor to ensure that your mezzanine meets all applicable building codes and safety standards.

Building code requirements for mezzanine railings vary depending on the specific codes of the jurisdiction where the building is located, but generaly, they are based on the International Building Code (IBC) and OSHA (Occupational Safety and Health Administration) requirements. Here are some of the common requirements for mezzanine railings according to ICB and OSHA:

• Guardrails ae required along the open sides of mezzanines, including the leading edge, to protect workers from falling. The top of the railings must be at least 42 inches above the walking surface of the mezzanine.
• The railings must be able to withstand a load of at least 200 pounds applied in any direction at any point along the top rail.
• Intermediate rails are required for mezzanines with a height of more than 30 inches above the floor level below.
• Openings: Openings in the railings must not allow the passage of a 4-inch diameter sphere.
• Stairway railings: Stairway railings are required along the open sides of the stairway leading to the mezzanine. The railings must be at least 36 inches high.