BS 8300 and LRV Contrast for Stair Nosings
BS 8300-2:2018 is the standard that puts a number on stair edge contrast: at least 30 points of Light Reflectance Value difference between the nosing and the surrounding tread.
It is a British Standard referenced by Approved Document M, not legislation in itself. That distinction matters when you are writing a specification: BS 8300 recommends, Part M guides, and the Building Regulations bind.
What LRV actually is
Light Reflectance Value measures how much visible light a surface reflects, on a scale from 0 (a theoretical perfect black) to 100 (a theoretical perfect white). Real materials sit inside that range — a matt black is around 5, a bright white around 85.
It is a measurement, not an opinion. Manufacturers of nosings, floor coverings and paints can supply LRV figures for their products, and the calculation is simple subtraction.
Why 30 points, and why eyes are not enough
Thirty points is the threshold at which the difference remains perceptible to someone with significantly reduced vision, and under poor lighting.
This is the crux: two colours that look obviously different to a sighted person in good light can measure within a handful of LRV points. Hue difference is not luminance difference. A mid-blue and a mid-green can look nothing alike and reflect almost identical amounts of light — and to someone with limited contrast sensitivity, or in a dim stairwell, they merge.
Common near-misses we see:
- Brushed aluminium on mid-grey vinyl — the classic office specification, and often under 20 points
- Brass on oak — warm tones with similar reflectance
- Any nosing on patterned carpet — the pattern averages out to a mid-tone, so contrast against it is weaker than against the lightest element in the design
- Black nosing on dark tread — visually smart, functionally invisible
How to check a combination
- Get the LRV of the tread surface from the flooring manufacturer.
- Get the LRV of the nosing or insert colour from the nosing supplier.
- Subtract. If the difference is 30 or more, you clear the BS 8300 recommendation.
Our LRV contrast calculator does the comparison for you.
If you cannot get an LRV figure from a supplier, treat that as a specification risk. On a tender-stage project it is worth having the numbers in writing.
Getting to 30 points in practice
The insert colour is doing most of the work, so choose it against the measured tread rather than against the profile finish.
- Dark treads — specify a light or high-visibility insert. Yellow and white give the largest available difference.
- Light treads — specify black or a dark insert. This is the direction people forget; contrast works both ways.
- Mid-tone treads — the hardest case, and where most specifications fail. You are choosing between going substantially lighter or substantially darker, and half-measures land short of 30.
- Powder coating is the practical route to a specific LRV when the standard insert colours will not reach the target.
Contrast is not slip resistance
These two get conflated constantly. Contrast addresses whether someone can see the step edge. Slip resistance addresses whether their foot stays on it. A nosing can be excellent at one and poor at the other.
Slip resistance is measured separately, by pendulum test, with an HSE benchmark of 36 PTV wet. More on slip testing.
Frequently asked questions
Is BS 8300 a legal requirement?
No. It is a British Standard referenced by Approved Document M. The Building Regulations bind; BS 8300 recommends. In practice, meeting its 30-point recommendation is the normal way of demonstrating that Part M's contrast provision has been addressed.
What LRV difference do I need?
At least 30 points between the nosing and the tread it sits against.
Can I judge contrast by eye?
No, and this is the most common cause of a failed specification. Hue difference is not luminance difference. Use measured LRV figures.
Where do I get LRV figures?
From the flooring manufacturer for the tread and the nosing supplier for the profile or insert. If a supplier cannot provide one, treat that as a risk on a project that has to be signed off.
Does the riser need to contrast too?
Approved Document M describes a 55mm band on both the tread and the riser, so yes — both faces need to read. More on Part M.
What about photoluminescent and illuminated nosings?
They address visibility in darkness. They do not remove the need for daytime contrast, so specify both where the stair is used in daylight as well.
See the full compliance guide, or browse stair nosings by colour and material.