What is the standard height of a stair guardrail?

The standard height of a stair guardrail is typically set at 42 inches, which is equal to 3 feet 6 inches. However, in many residential applications, guardrails are often set at a height that can be seen as 3 feet. The minimum requirement is usually 36 inches for guardrails surrounding the stairs early in a project design to ensure safety and prevention of falls.

While option C suggests a height of 2 feet, which is below the standard safety requirements for guardrails, particularly in commercial building codes, it is important to understand that in many jurisdictions, the accepted minimum for guardrails around stairs is indeed higher than that. Guardrails serve to provide safety to people using the stairs, and thus, ensuring proper height is critical for effective restriction against falls.

The other options, which suggest heights of 4 feet and 6 feet, exceed the common regulatory requirements for guardrails surrounding stairs. These heights would typically only be applicable to specific conditions or as part of protective barriers in larger public spaces, rather than standard stair railings. Standard stair guardrails are designed specifically to maintain a balance between safety and practicality, which aligns with the requirement for them to be around 3-4 feet above the walking surface to ensure adequate protection