The document discusses requirements for stairs according to various building codes. Stairs must be a permanent fixed construction and used as the main exit path for buildings over two stories. Stair components like landings, treads, and risers must meet specific dimension requirements to ensure safety. Handrails and guards are also required components, and stairs must provide adequate headroom clearance. Outside stairs need separation from the building interior and openings below protected for fire safety.

1. • Stairs are used as a component of means of egress.
• Buildings which are more than two storied, stairs are used as the main path of exit.
• All stairs serving as required means of egress shall be permanent fixed construction,
unless they are stairs serving seating that is designed to be repositioned.
STAIRWAYS
Components of Stairways:
1. Landings
2. Tread
3. Riser
4. Headroom
5. Handrails
6. Guards

2. BNBC
• Sum of riser height & tread depth shall be between
400mm and 425mm.
• Maximum riser depth 215mm
• Minimum tread depth 215mm
• Minimum clear head room 2.15m
• Maximum number of rises
NFPA
STAIRWAYS

3. Special Note
The landing between two stair flights in a straight run
shall not be required to be wider than 1.2m in the
direction of travel.
Visual Protection of Outside Stair
Outside stairs shall be arranged to avoid any impediments to
the use of the stairs by persons having a fear of high places.
For stairs more than three stories in height, any
arrangement intended to meet this requirement shall be not
less than 4 ft (1.2 m) in height.
STAIRWAYS

4. STAIRWAY WITH NONRATED/UNPROTECTED EXTERIOR WALL
 Separation & Protection: Outside stairs shall be separated from the interior of
the building by walls with fire resistance rating required for enclosed stairs
with fixed or self closing opening protectives. This construction shall extend
vertically from the ground to a point 10 ft ( 3m) above the top most landing of
the stairs or to the roofline, whichever is lower, and to a point not less than 10
ft horizontally.
If the exterior wall of the stair is flush with the building exterior wall, the fire would
need to travel around 180degrees in order to impact the stair. This has not been a
problem in existing buildings, so no protection is required. However,
if the angle of exposure is less than 180 degrees, protection of either the stair wall or
building wall is required.
STAIRWAYS

5. BNBC:
Where the width of the stair exceeds 2.2m, intermediate handrails shall
be provided so that no point on the stair is farther than 1 m from the
handrails.
STAIRWAYS

6. Spiral & Winding stairways shall be permitted as an element of a means of escape only
a. Dwelling unit
b. Mezzanine floor not more than 25m2 in area
STAIRWAYS
Spiral & Winding stairways shall be permitted as an
element of a means of escape only
a. Minimum width of such stairway 650 mm
b. Each tread having a minimum depth of 200mm
at a distance of 300mm from the narrower end.
c. The rise shall not be more than 225 mm with a
permissible tolerance of 5mm between adjacent
risers and 10 mm between the largest and
smallest risers.

7.  Protection of openings: All openings below an outside stairs shall have a minimum ¾ hour fire
rating.
 Openness: outside stairs shall be not less than 50% open on one side. Outside stairs shall be
arranged to restrict the accumulation of smoke.
STAIRWAYS