If you are specifying stairs for a commercial building, a block of flats, a school or a rented property, sooner or later someone will ask whether your stair nosings comply. This guide sets out what Approved Documents K and M actually say, what the dimensions are, and where the requirements differ between a private house and a public building.
One point before the detail. Approved Documents are guidance on how to meet the Building Regulations — they are not the Regulations themselves. You can meet the requirements another way, provided you can demonstrate it. In practice, following the guidance is the simplest route through Building Control.
Which Documents Apply
Approved Document K — Protection from falling, collision and impact. This is the document that deals with stairs as a physical hazard: steepness, rise and going, handrails, headroom and the step edge itself. It defines the nosing simply as the leading edge of a stair tread.
Approved Document M — Access to and use of buildings. This is where the visibility requirements sit. Most of the specific figures people quote for stair nosings come from Part M rather than Part K.
BS 8300-2:2018 covers accessible and inclusive design. It is a British Standard rather than a regulation, but it is widely used as the benchmark on projects where accessibility is being taken seriously.
These apply in England. Wales, Scotland and Northern Ireland have their own building standards, and the figures are not always identical — check the relevant document if your project is outside England.
The Dimensions
Buildings other than dwellings — offices, schools, shops, hospitals, public buildings. Step nosings should be made visually apparent using a material that contrasts visually, a minimum of 55mm wide on both the tread and the riser.
Common access areas in buildings containing flats — the guidance gives a range rather than a minimum: 50 to 65mm wide on the tread, and 30 to 55mm on the riser.
Note that both figures cover the tread and the riser. A profile that marks only the top surface does not meet the guidance on its own.
Protrusion and Trip Hazards
Where possible, nosings that project out over the tread below should be avoided altogether. Where a nosing does protrude, the guidance is that it should do so by no more than 25mm.
The reason is straightforward. A projecting edge catches the toe of a shoe on the way up, and it is a particular problem for anyone using a walking aid. It is also why open risers are discouraged — a foot or a stick can pass under the tread.
Visual Contrast and LRV
"Contrasting visually" is not a matter of opinion. The usual measure is Light Reflectance Value, a scale from 0 (black) to 100 (white). BS 8300-2:2018 recommends a difference of at least 30 LRV points between the nosing and the surrounding tread.
In practice this means a dark profile on pale steps, or a light profile on dark steps. A silver nosing on a grey concrete stair may look smart, but the LRV difference is often well under 30 and it will not satisfy an access consultant.
The contrast also has to be permanent. A painted line wears through at exactly the point where it matters most, which is why anodised and inlaid finishes are specified instead.
Slip Resistance
Part K requires stairs to be safe in use, which in a public building means the step edge needs adequate slip resistance. This is where ribbed treads and rubber inserts come in — a plain metal surface offers very little grip, particularly when wet.
For stairs in constant use, or anywhere water may be walked in, rubber-insert profiles are the usual specification. The insert can also be replaced when it wears, without taking the profile off the step.
Consistency Across the Flight
An easily missed point: every nosing in a flight should be identical, and the rise and going should be consistent from step to step. The eye reads a staircase as a series of parallel lines, and an inconsistent step edge creates a genuine hazard — someone descending judges the next step from the pattern, not by looking at each one.
If you are replacing damaged nosings on an existing stair, match the profile rather than fitting whatever is to hand.
Fire Escape Routes
On escape routes, Approved Document B (fire safety) becomes relevant. Photoluminescent nosings that stay visible after a power failure are often specified in stairwells and other escape routes in commercial buildings. If your project involves a designated escape route, check what your fire strategy requires before ordering.
Do Private Homes Need Compliant Nosings?
The detailed visibility requirements above apply to buildings other than dwellings, and to the common areas of blocks of flats. Inside a private house they are not applied in the same way.
That said, the reasoning behind them does not stop at the front door. Most stair falls happen on the way down, when the eye is judging where one step ends and the next begins — and that is as true at home as it is in an office. On stairs used by older people or young children, a contrasting, slip-resistant edge is worth fitting whether or not anyone is going to inspect it.
Landlords, Employers and Building Managers
Building Regulations apply to building work. Separately, if you are an employer or you control a workplace, you carry a duty to keep stairs safe under health and safety law, and the Equality Act 2010 requires reasonable adjustments for disabled people using your building.
The Regulations rarely name stair nosings outright. But between the duty to keep stairs safe and the duty to make a building accessible, slip-resistant and visually contrasting step edges are in practice difficult to avoid in any building the public uses.
A Quick Compliance Check
- Is the contrasting band at least 55mm wide on both tread and riser? (50–65mm tread / 30–55mm riser in common areas of flats)
- Is there at least 30 LRV points of difference between the nosing and the tread?
- Is the contrast permanent rather than painted on?
- Does the profile project over the tread below by more than 25mm?
- Is the tread surface slip-resistant?
- Is every nosing in the flight the same, and correctly aligned?
Choosing a Compliant Profile
Our range includes profiles suited to commercial and public-building specifications. For high-traffic stairs where grip is the priority, see stair nosing with rubber inserts. For escape routes and low-light areas, see glow-in-the-dark stair nosings and LED stair nosings. For heavy-duty commercial use, see commercial stair nosing.
Working to a specification and not sure which profile fits? Call us on 07452 792 733 or send us the details. Contractors and specifiers can also apply for a trade account for volume pricing.
Frequently Asked Questions
Are stair nosings a legal requirement in the UK?
The Regulations do not name them directly. But in buildings other than dwellings, step edges are expected to be visually apparent and slip-resistant, and a nosing is the normal way of achieving both. In practice they are difficult to avoid in a public or commercial building.
How wide does the contrasting band need to be?
Minimum 55mm on both the tread and the riser in buildings other than dwellings. In common areas of buildings containing flats, 50–65mm on the tread and 30–55mm on the riser.
What does 30 LRV points actually mean?
Light Reflectance Value measures how much light a surface reflects, from 0 to 100. If your tread has an LRV of 55, the nosing needs to be below 25 or above 85. Manufacturers publish LRV figures for finishes — ask if you need them for a submission.
Do I need Building Control approval to fit stair nosings?
Replacing nosings on an existing staircase does not normally require approval. New builds and material alterations do, and the stair specification will be looked at as part of that.
Do these rules apply in Scotland?
Scotland has its own Building Standards, as do Wales and Northern Ireland. The principles are similar but the detail differs — check the relevant technical handbook for your project.
Can I bring an old staircase up to standard?
Often, yes. Retrofitting compliant nosings to a sound existing stair is common in refurbishment work. The tread edges need to be solid and reasonably level first.
This guide is intended as general information, not as advice for a specific project. Building Regulations are updated from time to time, and requirements differ between England, Wales, Scotland and Northern Ireland. For a live project, confirm the current requirements with your Building Control body or an access consultant.