As with all areas of development and construction, the world of accessible design is filled with complex terminology. From product terms like Thermostatic Mixer Valves to legislative terms such as BS8300, there's a lot of vocabulary to keep up with.
One such term that makes the list is Light Reflectance Value, or LRV for short. So, what is Light Reflectance Value?
Definition of Light Reflectance Value
Light Reflectance Value is a percentage figure given to a surface that represents the amount of visible light it reflects when illuminated by a light source.
As an example, the above chart shows the LRV of different shades of grey between white and black:
White holds the highest LRV, reflecting 100% of the light that hits it, and black holds the lowest, absorbing all the light and reflecting none. The shades in between reflect varying levels.
The same is true for other colours beyond black and white.
What is Light Reflectance Value used for?
Primarily, LRV is used to ensure that a built environment is suitably lit.
Architects, interior designers and colour consultants would all use LRVs alongside the lumen rating of their light fittings to ensure that each and every room is lit to an acceptable standard.
How is LRV used within accessible design?
Light Reflectance Value is used extensively within accessible design. It's a crucial factor when considering how to make a space accessible for those with a visual impairment.
Certain fixtures need to contrast visually with the surface to which they are fixed so that they are easier to identify to those with partial sight. Even the floor and the walls need to contrast so that the user can more easily see where the boundaries of the room are.
To qualify, the two colours have to differ by more than 30 points. Where the surfaces are lit by more than 200 lux, the two colours must differ by a minimum of 20 points. And (to make things extra complex) “where door opening furniture projects beyond the face of the door or otherwise creates enhanced differentiation and shade, a minimum difference in light reflectance value of 15 points is considered adequate”, according to Doc M, Volume 2.
How do NYMAS use Light Reflectance Value?
NYMAS consider the proper use of LRV throughout our range. The most relevant products can include:
· Grab rails
· Hinged rails
· Toilet seats
· Back rests
· Shower seats
Not all of these require a visual contrast in LRV, but if accessibility is your goal then it helps to tick as many boxes as possible.
How should you use LRV in your project?
As always when it comes to accessible design, our team have all the answers. If you have any questions, pick up the phone and call +44 (0)1642 710 719, or email firstname.lastname@example.org for some expert advice.