Private stair rise, going and pitch

Rise 155–220 mm, going at least 220 mm, maximum pitch 42°, and twice the rise plus the going between 550 mm and 700 mm

Private stair within a single dwelling

Tolerance: All rises in a flight must be equal

Every figure for this topic is on one page: Stair dimensions and handrail heights in UK homes

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Dimensional limits for a stair serving a single dwelling.

Rise and going are measured on consistent steps, with the pitch line taken across the nosings.Original ProPlot drawing, not to scale. Geometry verified against Approved Document K, protection from falling, collision and impact.

Basis in regulation

Part K
Approved Document K
Read the source

How to check it on site

Measure the first and last rise as built — floor finishes added later are the usual cause of an unequal step.

Common failure

A short top or bottom riser once the floor finish is laid, and inconsistent rises across the flight.

Effective from 20 August 2026. Last updated 23 August 2026. This is our editorial summary of publicly available regulation, not building control approval or a warranty determination.

Related dimensions at this stage

Minimum

Hearth Provision and Floor Finishes

225 mm

A hearth may not be necessary if an appliance's flame or incandescent material is positioned at least 225mm above the floor

Minimum

Soundproofing Measures for Soil Pipes

25 mm

Sound insulation for soil pipes involves either encasing them in boxing made from a material with a minimum mass of 15kg/m², or wrapping them with at least 25mm of unfaced mineral wool, typically 10kg/m³ density

Minimum

Electrical Accessory Clearance from Water Diagrams

300 mm

Diagrams illustrating the required 300mm minimum horizontal clearance for electrical accessories from water sources, such as sinks and wash basins, are commonly used in guidance documents

exact

Conditions for Pipe Freezing Calculations

6 °C

Calculations for pipe insulation to prevent freezing are based on specific assumed conditions, typically including an external air temperature of -6°C and an internal water temperature of +7°C

Minimum

Water seal depth at appliance traps

75 mm for baths, basins, sinks and showers on a branch; 50 mm for a WC trap

Appliance trap on a branch discharge pipe

Minimum

Stair Handrail Height and Clearance

600 mm

A handrail is mandatory for flights of stairs where the rise exceeds 600mm