Part K protection from falling collision and impact

Part K for Risk Management Surveyors


Risers, Goings and stair construction

  • Riser = vertical part of step, going = horizontal part of step
  • Maximum pitch of stairs is to be 42 degrees
  • For a private stairs risers should be 150-220mm
  • For a private stairs, goings should be 220-300mm
  • Relationship between (2R+G ) – 550mm 700mm
  • Open risers can only be used in dwellings
  • Where using Open risers 100mm sphere gap max & overlap treads by 16mm minimum
  • In common areas of flats treads should have contrast nosing 50-65mm wide on tread


Headroom for stairs

  • All means of escape routes should have a minimum clear headroom of 2m except in doorways
  • Measure from the lowest point of the bulkhead and from the pitch line of the stairs
  • You can have reduced head room to 1.8m for loft conversions

Width of stairs & Landings

  • For commercial units the stairs should be split if more than 2m wide into 1m wide
  • No minimum width for private stairs & 30degree change of direction if >36 flights
  • A door can swing across a landing but has to leave a 400mm gap between stair & door
  • For tapered stairs minimum tread width 50mm at narrow end


Handrails for stairs

  • Handrail to be 900-1000mm from stair pitch line
  • If stairs are 1000mm or wider handrails to be provided on both sides
  • In buildings other than dwellings and common areas for flats, handrail needed for each side of flights and landings; continuous handrail along the flights and landings
  • Other than dwellings; handrails should not project into access route and ensure handrail contrasts visually with background
  • Handrail to be slip resistant, and turned down to stop clothes snagging


Guarding for stairs

  • 100mm sphere
  • Shouldn’t be climbable for children
  • Common areas guarding needed where there are 2+ risers
  • In dwellings, provide guarding where there is a drop of 600mm plus




  • Ramps should be apparent and signed
  • Minimum 1:12 maximum 1:20, see table in K1:2 for goings and risers


  • Dwellings – Internal 900mm minimum height & external 1100mm
  • Glazing – Window openings guarding height 8oomm min


Protection against impact with glazing – Critical areas

  • 800mm in windows and side panels
  • 1500mm in doors

Why is a level balcony threshold dangerous?

Part M of the building regulations concerns access to and use of buildings. It requires that access is designed in a way that enables all people to use a building and its facilities. The door thresholds should be a maximum of 15mm to meet part M requirements. Continue reading Why is a level balcony threshold dangerous?

Reinforcing concrete & cover

It is important when inspecting reinforcing bars that they are clean and free of loose rust. They should be placed in accordance with the structural engineers drawings, usually made up of main and secondary bars. When inspecting reinforcement you have to make sure that the laps are sufficient, and it’s usually 40x the diameter of the bar being used. Continue reading Reinforcing concrete & cover