What are the stair regulations for a house in England?
For a private stair in a house, Approved Document K gives a rise of 150 to 220 mm, a going of 220 to 300 mm and a pitch of no more than 42 degrees. It also sets out headroom, handrails, guarding and landings.
Rise, going and pitch
Requirement K1 says stairs must be designed, built and installed to be safe for people moving between levels. Approved Document K is the official guidance on how to meet it. A private stair is one used by only one dwelling. For a private stair, Table 1.1 gives:
- Rise: 150 mm minimum, 220 mm maximum.
- Going: 220 mm minimum, 300 mm maximum.
- Pitch: 42 degrees maximum.
- Twice the rise plus the going (2R + G) normally comes to between 550 mm and 700 mm.
Measure the going from nosing to nosing. Every step in a flight should have the same rise and going. You can mix any rise and any going from the ranges, as long as the pitch and the 2R + G sum still work. The steepest rise with the shortest going would be 45 degrees, so that combination fails the pitch limit.
In a house, open risers are allowed if the treads overlap by at least 16 mm and a 100 mm sphere cannot pass through the gaps.
Headroom
Approved Document K shows a minimum headroom of 2 m on the access between levels, over the flight and the landings.
For a loft conversion in a dwelling, where there is not enough height for 2 m, it accepts a reduced headroom: 1.9 m over the middle of the stair, dropping to 1.8 m at the side of the stair.
Handrails
The guidance is to put the top of the handrail 900 mm to 1000 mm above the pitch line, or above the floor on a landing. The handrail can form the top of the guarding if the heights match.
Where the stair is 1000 mm wide or more, provide a handrail on both sides.
Guarding and the 100 mm sphere
In a dwelling, Approved Document K says to guard the sides of flights and landings where there is a drop of more than 600 mm.
- Guarding height in a single-family dwelling is 900 mm for stairs, landings and the edges of internal floors.
- External balconies, including Juliet balconies, and roof edges need 1100 mm.
- Where children under five may use the building, no opening in the guarding should let a 100 mm sphere through, and the guarding should not be easy to climb, so avoid horizontal rails.
Guarding should also resist the loads given in the standards the document lists, so check the balustrade system is rated for it.
Landings and long flights
Provide a landing at the top and bottom of every flight. It should be at least as wide and as long as the narrowest width of the flight, and kept clear of permanent obstructions.
- Landings should be level. The exception is a landing formed by firm, paved ground, which can fall by no more than 1 in 60 in the direction of travel.
- Cupboard doors may open over a landing at the top of a flight only if they are kept shut when in normal use.
- In a dwelling, a door may swing across a landing at the bottom of a flight, but only in the arrangement shown in Diagram 1.8.
- If consecutive flights have more than 36 risers, include at least one change of direction.
Before you build
Approved Document K is guidance. Following it gives a presumption of compliance, but there are other ways to comply, and the document says to discuss any other approach with the building control body.
For stairs in existing buildings, the document says to follow the Table 1.1 sizes unless the layout makes that impossible, and to agree any alternative with building control. Part K applies to stairs that are part of the building, not to steps on land leading up to it.