What is the minimum clear height over a stair in a secondary suite located under a beam or duct?

The minimum clear height over a stair in a secondary suite located under a beam or duct is 1850mm. This standard is set to ensure safety and accessibility for users of the stairs. It allows enough headroom for people to move comfortably without risk of bumping their heads on overhead obstructions.

In residential construction, particularly within secondary suites, clear height requirements help mitigate hazards associated with height constraints. The provision of 1850mm is particularly important as it aligns with the intention to maintain an accessible and safe environment in living spaces, accommodating various occupants, including those who may be taller or have mobility challenges.

In this context, other height values like 1700mm, 1800mm, and 1900mm do not meet the established safety and accessibility standards for stair clearances. The values below 1850mm could result in an unsafe environment if users were to hit their heads, creating a risk of injury. On the other hand, while 1900mm is certainly more generous, it exceeds the minimum requirement, which aims to find a balance between safety and practical architectural considerations.