LIGHT REFLECTANCE VALUES (LRV)
In architecture, Light Reflectance Values (LRV), are a measure of the percentage of visible and usable light that is reflected from a surface when illuminated by a light source.
Why are Light Reflectance Values important?
Legislation (Equality Act 2010) requires that all new and refurbished public buildings and work places comply with current regulations via their ‘Access Statement’, ensuring safe entry, exit and safe passage throughout the building.
The regulations mean that people, regardless of disability, age or gender, must be able to gain equal access to public buildings. For visually impaired people this means amongst other things that there must be a good visual contrast between various elements of the building, including doorways, fixtures and fittings. Therefore the contrast between, for example, floors and walls must achieve a certain level – measured by something called Light Reflectance Value (LRV).
What are Light Reflectance Values?
• LRV is a universal value for ‘contrast’
• It measures the proportion of useful light reflected by a coloured object
• It represents a relative light and darkness value rather than an actual colour. Therefore dissimilar colours could have the same LRV
• LRV is measured on a scale of 0 to 100, 0 being perfect absorbing black and 100 being perfect reflecting white (in reality you never find these perfect objects – a bright white would typically have a result of an LRV of 85)
• A minimum of 30 points LRV difference is advised for adjacent surfaces
Walls to floor = 43 points contrast
**By viewing black and white image of the adjacent colour scheme the tonal differences of the colours become apparent.
Why do we need Contrast?
Most registered blind people will still have some vision in colour. Only a small percentage (less than 5%) can see nothing at all, and even people within this group will generally have some sensitivity to light and shade. So therefore ensuring that a minimum of 30 points of LRV difference is specified for adjacent surfaces will in the majority of cases help to ensure that visually impaired people are not discriminated against.
Examples where visual contrast will be required:
• Door faces and/or frames to walls
• Floors to Walls
• Ceilings to Walls
• Handrails to Walls
• Sanitary fittings to walls
Stair-treads
From front edge corner, 55mm on tread and 55mm down the riser.
For further information or advice, please call us on 0845 130 2241 or email mail@grestec.co.uk and we’ll be happy to help.
You can download our free LRV Advice eBook here.