Maximum length of a flight of stairs
Approved Document K requires that dwellings with more than 36 risers in consecutive flights of stairs, have at least one change of direction, with a landing that has a minimum length equal to the width of the stairs.
For buildings other than dwellings, the maximum number of risers between landings is 16 for utility stairs, and 12 for general access stairs (or 16 in exceptional circumstances where the plan area is restricted). There should not be any single steps.
A utility stair is '...a stair used for escape, access for maintenance, or purposes other than as the usual route for moving between levels on a day-to-day basis.'
A general access is '...a stair intended for all users of a building on a day-to-day basis, as a normal route between levels.’
The requirements for the rise and going of stairs are set out below:
| Min rise (mm) | Max rise (mm) | Min going (mm) | Max going (mm) | |
| Private stair | 150 | 220 | 220 | 300 |
| Utility stair | 150 | 190 | 250 | 400 |
| General access stair | 150 | 170 | 250 | 400 |
This gives, for example, a maximum pitch for a private stair of 42 degrees.
The normal relationship between the rise and the going is that 2 x the rise + the going should be between 550mm and 700mm.
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