Stair building regulations

The limits Approved Document K sets for the steps of a staircase in England, in one place. Work out your own stair with the stair calculator.

Rise and going

The rise is the height of each step. The going is the depth of each tread, measured nosing to nosing. Every step in a flight should have the same rise and going.

Approved Document K, Table 1.1
Kind of stair	Rise	Going
Private stair a stair in a home	150 to 220 mm	220 to 300 mm
Utility stair escape stairs and stairs used by few people, not in homes	150 to 190 mm	250 to 400 mm
General access stair stairs in public and shared buildings	150 to 170 mm	250 to 400 mm

Approved Document K, Table 1.1

Kind of stair

Rise

Going

Private stair
a stair in a home

150 to 220 mm

220 to 300 mm

Utility stair
escape stairs and stairs used by few people, not in homes

150 to 190 mm

250 to 400 mm

General access stair
stairs in public and shared buildings

150 to 170 mm

250 to 400 mm

For every kind of stair, twice the rise plus the going should come to between 550 mm and 700 mm. A private stair should be no steeper than 42°.

Number of steps in a flight

Outside homes, a utility stair should have no more than 16 risers between landings, and a general access stair no more than 12, or exceptionally up to 16 in small premises where space is tight.

Headroom

Allow at least 2 m of headroom over the stair, measured up from the pitch line. In a loft conversion where there is not room for that, 1.9 m at the centre of the stair and 1.8 m at the side is acceptable.

Guarding

In a home, the sides of a flight or landing need guarding where there is a drop of more than 600 mm.

Where this comes from

Approved Document K: protection from falling, collision and impact, 2013 edition (GOV.UK). It applies in England; Wales, Scotland and Northern Ireland have their own building regulations. Approved Documents are guidance on meeting the regulations: your building control body decides whether work meets them. Checked 13 November 2026.