Simplified Stair Rules :

This is a simplified set of guidelines describing the most common aspects in a stair design for dwellings. Formal and complete guidance is provided within The Building Regulations Annex K – Protection from falling, collision and impact for certified guidelines and anything other than dwellings.

Rise & Going:

  • Stair must meet the following rise and going limitations
  • * Stair Rule – 2 x Rise + Going
  • ** 170-200 is generally preferred
  • Min going on smallest part of winders = 50mm
  • For stairs < 1m wide, going is measured in the middle,
  • For stairs >1m wide, going measured at 270mm from each side
TypeRise (mm)Going (mm)Stair Rule *
Private150-220 **220-300550-700
General Access150-170250-400


  • Must be >2m all locations on flights and landing, (note more headroom provides feeling of space)
  • ­For Loft conversions permissible >1.9m middle of stair, >1.8 at lowest point.


  • Mid-flight landing steps should be at least as wide and long as the smallest stair width
  • ­Must be clear of permanent obstructions
  • ­Cupboard doors may open over landings, but minimum unobstructed free space of 400mm.
  • ­Top/bottom landings should be level, but can be up to 1:60 slope if paved or appropriately firm
  • ­Door may swing across landing (bottom only) providing unobstructed free space of 400mm from 1st tread.

Alternative tread stairs:

Allowable for loft conversions only if insufficient space to satisfy other requirements

Open Risers:

Permissible in dwellings provided there is a minimum gap of 100mm and treads overlap >16mm


  • Top of handrail between 900mm and 1000mm from pitch/nosing line or floor
  • ­Handrail is required on one side of stair, and on both sides if the stair width is >1000mm

Balustrade / Guarding:

  • ­Unless exemption from children <5, Must prevent 100mm sphere passing through & be resistant to children climbing
  • Required on flight and landings >600mm high
  • ­Be of sufficient strength and level of safety (e.g. glass breaking), see building regulations for details

And if you want to know more …

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