In England, the design of stairs is covered by Approved Document K of the Building Regulations. It sets limits on the size of each step, the steepness of the stair, headroom, handrails and guarding. The figures depend on who uses the stair.
Rise and going
The rise is the height of each step; the going is the depth of the tread, measured nosing to nosing. Approved Document K groups stairs into three categories:
- Private stair (within one dwelling): rise 150-220 mm, going 220-300 mm
- Utility stair (for example escape or maintenance access): rise 150-190 mm, going 250-400 mm
- General access stair (shared or public use): rise 150-170 mm, going 250-400 mm
All the rises in a flight should be equal, and so should all the goings. A comfortable stride is checked with twice the rise plus the going, which should fall between 550 and 700 mm.
Pitch
A private stair must be no steeper than 42 degrees. For other categories, the rise and going limits keep the stair shallower.
Headroom
Allow at least 2000 mm clear headroom over the stair, measured vertically from the pitch line. There is a relaxation for loft conversions where there is not enough height: 1900 mm at the centre of the stair, reducing to 1800 mm at the side.
Handrails
- Stairs less than 1 m wide need a handrail on at least one side; wider stairs need handrails on both sides
- Handrails are typically 900-1000 mm above the pitch line and on landings
- They should be easy to grip and run the full length of the flight
Guarding
Open sides of stairs and landings need guarding. In a house this is typically 900 mm high on stairs and landings, and gaps must not let a 100 mm sphere pass through. Open risers are allowed in many cases if treads overlap by at least 16 mm and the 100 mm rule is met.
Landings
Provide a level landing at the top and bottom of every flight, at least as wide and as long as the stair is wide. Doors should not swing across the landing in a way that blocks it.
Want to check a stair quickly? Our staircase calculator works out the risers and checks the rise, going, pitch and 2R + G for you.
General guidance for England. Your designer and building control confirm the requirements for your project.