Light reflectance value

Guidance

Designers of buildings must comply with the building codes applicable to the structure under consideration. Since 2004 guidance has existed on access to and use of buildings. The guidance is particularly concerned with provisions to assist the disabled, including those who are visually impaired. The guidance highlights the need for certain surfaces and features to contrast visually with their surroundings. Areas of particular interest are wall-to-ceiling and wall-to-floor junctions, exposed edges of sloping floors, seating and its surroundings, leading edges of doors, door opening furniture and door surfaces, sanitary fittings and grab bars.

This is relevant to a wide range of non-residential buildings, such as hospitals, schools, hotels, and theatres.

Codes of practice

The British Standards Institute's guidance in the Regulations and in the relevant Codes of Practice, BS 8300:2018, is that adequate visual contrast is provided if the light reflectance values of the contrasting areas differ by at least thirty points. The current British Standard for the measurement of LRV is BS8493:2008+A1:2010.

The Americans with Disabilities Act Standards for Accessible Design does not recommend a light reflectance value for contrast on signage with words or pictograms, but instead it provides that "characters shall contrast with their background with either light characters on a dark background or dark characters on a light background" in § 703.5.1

The International Code Council utilizes the ADA approach and does not use a light reflectance value in the 2017 update to the standards for ICC A117.1 in § 703.5.3.2

The United Nations Economic Commission for Europe uses a difference of sixty points between the LRVs for the contrast requirement of signage in "Railway Applications — Design for PRM Use - General Requirements — Part 1: Contrast."

Manufacturers are advised by the Guild of Architectural Ironmongery to publish the LRV for their products.

References

• Bradshaw, Vaugh, P.E. Building Control Systems. New York: John Wiley & Sons, Inc. Second Edition, 1993.

References

1. "Specification Guidelines, Design Service & CPD". gradusworld.com.
2. "ADA Standards for Accessible Design (2010)".
3. "International Code Council 'Accessible and Usable Buildings and Facilities (2017)'".
4. "United Nations Economic Commission for Europe 'Railway Applications — Design for PRM Use - General Requirements — Part 1: Contrast.'".