Stair headroom clearance is the vertical distance between the nose of the stair tread and the underside of the ceiling directly above it. The minimum required headroom clearance varies by jurisdiction, but it is typically around 6 feet 8 inches.
Calculating Stair Headroom Clearance for New Construction
Draw the Stairway: Draw a detailed sketch of the lower and upper floors, stairway, including the tread depth, riser height, and overall dimensions.
Determine the Rise and Run: The rise is the vertical distance between two treads, and the run is the horizontal distance between the front edges of two treads.
Calculate the Total Rise: Multiply the number of risers by the rise height to determine the total vertical distance from the floor to the underside of the ceiling.
Calculating Stair Headroom Clearance for Existing Buildings
Measure the Headroom Clearance: Place a plumb bob or other measuring device at the nose of the stair tread and measure the vertical distance to the underside of the ceiling. Compare this measurement to the required headroom clearance. If the measurement is less than the required clearance, adjust the design of the stairway until it meets code requirements.
Adjusting Stair Headroom Clearance
Increase the Rise: Increase the height of each riser, but be sure to maintain a comfortable step ratio of 7 to 10 inches.
Decrease the Run: Decrease the horizontal distance between the front edges of two treads.
Move the Stairway: If possible, move the stairway to a different location where there is more headroom.
Lower the Landing or Floor Below: If the space below the stairs allows, lowering the landing or the floor underneath can increase headroom. This is a significant undertaking involving structural adjustments.
Raise the Ceiling: In some cases, raising the ceiling above the stairs might be feasible. This could involve raising the roof, adding a dormer, or modifying ceiling joists. Consult a structural engineer before attempting any ceiling modifications.
Reconfigure the Staircase: Rebuilding the staircase with a steeper pitch or a winder configuration can sometimes increase headroom. This is a major project requiring professional expertise.
Important Considerations
Building codes may have specific requirements for stair headroom clearance, so be sure to consult local building codes before making any changes to your stairway.
Stair headroom clearance is important for both adults and children. It is especially important to ensure that there is adequate headroom for children to walk under the stairs without hitting their head.
