A Guide to Building Regulations Part K


Regulations Part K is an essential regulatory guideline that standardizes certain safety components of a house with special emphasis on the stairways, ladders, ramps and guards. The technical guidance that these rules can provide is extremely important, promoting minimum safety standards in the home environment. Let’s take a look at these regulations in a more detailed fashion.

Building Regulations Part K: Stairways

One of the most important elements of building regulations Part K stairs is the section about safe passage. The stairways have to allow safe passage under all circumstances, otherwise, they cannot be regulated. The rise, going and pitch all have to be of appropriate dimensions as well, meaning:

  • Every step must have the same rise
  • Every parallel step must have the same going
  • All tapered steps must have the same going

Part K building regs also state optimum and maximum values, depending on the status of the staircase. There are three different statuses for the stairs, private, semi-public and public, each having slightly different regulations.

Private means that the staircase is only used by a limited number of people, semi-public means it is used by a larger number of people, some of whom may not be familiar with the stairs. Lastly, public means that the staircase is used frequently by a large number of people, like the staircase of a restaurant for example.

With a private staircase, the rise can start at 175mm and can be as high as 220mm, whereas with a public staircase these values have to fall between 150 and 180. These are specific regulations that have to be followed to the tee.

In addition, the headroom over the stairs has to be at least 200mm, unless the space is very limited, like in a house for example. Even in those places, however, the minimum headroom cannot be lower than 180mm. This is important for obvious safety reasons.

Part K Building Regulations: The width of stairs

stair-regulations-diagramPrivate stairs should have a width of no less than 800mm. With semi-public or public stairs, the designers have to be complacent about other regulations as well, including a “means of escape” that has to pass fire safety regulations, as well as providing access to ambulant disabled people. Without these, the staircase cannot be regulated.

Length of flights

  • No more than 16 risers
  • No more than two consecutive flights, each with a maximum of 12 risers
  • At least 30° between the flights


Building regulation part K states that a ladder has to have fixed handrails on both sides, and should not be used as a primary access to a habitable room.


If the stairs are 1000mm wide or less than that, they must have a handrail on at least one side. If they are wider than that, getting a handrail installed on both sides is mandatory. Building regulations Part K also states that the top surface of the handrail should fall somewhere between 900mm and 1000mm.


If the total rise does not exceed 600mm, installing some kind of guarding is not mandatory. If, however, it ends up exceeding it, guarding becomes essential. Suitable solutions can include a wall or a screen (the screen can be glazed), railing or balustrade. Guarding must be designed and constructed in a way that it does not create extra risks. If the guarding contains glazing, there are extra regulation steps that one has to take, precisely the recommendations of BS 6262-4, 2005.

If there are children younger than five years old in the building, the guarding has to be constructed in a way that it does not allow a 100mm diameter sphere to pass through any of the possible openings. It’s best if there are no such openings, and the guarding should also not be easily climbable and should be designed in a way that would discourage kids from trying to climb it. Any feature that could essentially act as a foothold should be outlined as well.

Further regulations

If a ramp is 1000mm or less, it should have a handrail on one side. If it is wider than 1000mm, a handrail should be installed on both sides. The handrails have to be between 900mm and 1000mm when measured vertically.

Building Regulations Part K (PDF)

This is a short video on a project for our staircase which involves making newel posts and fitting pipes/rails instead of balustrades. Inspired by Grand Designs this is a project in our own home. The staircase is built to part K of the UK building regulations.

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