What are the rise and going limits for domestic stairs?

For private domestic stairs (Part K): maximum rise 220mm, minimum going 220mm. The rise should be between 150-220mm and the going between 220-300mm. All steps must have uniform rise and going. The 2R+G formula (twice rise plus going) should be between 550-700mm for comfortable use.

What is the maximum stair pitch?

The maximum pitch for domestic stairs is 42 degrees. For common stairs in flats: 38 degrees. For institutional and assembly buildings: 38 degrees. The pitch is determined by the relationship between rise and going: steeper stairs have larger rises relative to goings.

What minimum headroom is required?

Minimum headroom is 2,000mm (2m) measured vertically from the pitch line (nosing to nosing line) to the ceiling or soffit above. This applies to all parts of the stairway including landings. For loft conversions where headroom is limited, a reduced headroom of 1,800mm may be accepted with appropriate design.

How wide should a domestic staircase be?

The minimum stair width for a domestic staircase is 800mm (clear between walls or between a wall and handrail). For common stairs in flats: 900mm minimum. For means of escape in non-domestic buildings, width is determined by occupant capacity. Most domestic stairs are 860-900mm for comfort.

What height should a stair handrail be?

Handrails must be 900-1000mm above the pitch line (nosing to nosing) for domestic stairs. Landing guarding must be at least 900mm high. Handrails are required on at least one side of stairs less than 1m wide, and both sides if wider than 1m. Handrails must be graspable (32-50mm diameter).

TradeCalculator

Part K Stair Calculator — Rise, Going, Pitch & Headroom

Check staircase dimensions against Part K limits including rise/going, maximum pitch 42 degrees, headroom 2m minimum and handrail height requirements.

Stair type

Total floor-to-floor rise

Proposed rise per step

Proposed going per step

Stair width

Headroom

How We Calculate This

This calculator checks proposed staircase dimensions against Approved Document K requirements.

Dimension checks

Rise: 150-220mm (domestic), 150-170mm (common)
Going: 220-300mm (domestic), 250-300mm (common)
Pitch: max 42° (domestic), 38° (others)
2R+G: 550-700mm for comfort
Headroom: min 2,000mm throughout

Frequently Asked Questions

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Last updated: March 2026

All calculations are estimates. Verify with your supplier.