When specifying steps for projects in the public realm, it is important to consider the light reflectance value (LRV) of the different surfaces of the step slabs selected. Using light reflectance values is a way to ensure that the individual steps are clearly defined for all users, including those who may be visually impaired.
The light reflectance value measures the percentage of visible and usable light that is reflected from a surface when illuminated by a light source. It is defined on a scale of 0% to 100%.
Zero percent represents a black surface with perfect light absorption. Conversely, one hundred percent equates to a white surface where all light is completely reflected:
There is some variance to these levels in real projects. For example, a typical black surface has an LRV of around 5% to 10% and a brilliant white surface is about 85%.
Light reflectance values are a good way to provide an accurate measure of the contrast between different surfaces. Specifiers in the public realm need to ensure that the edge of each step, otherwise known as the nosing, has sufficient contrast to stand out against the background colours of the treads and risers.
This can be achieved by using step slabs, also sometimes referred to as step flags, and step units with contrasting nosings. Building regulations state that sufficient contrast is achieved when the difference in light reflectance values between two surfaces is greater than 30 percentage points. This enables specifiers to check a manufacturer’s product data and confirm that the products they are looking to specify will be suitable for their project.
Step slabs and step units, both with contrasting nosings, are examples of products with an integral black nosing that provides the necessary 30-point difference.
As well as ensuring the steps themselves are clearly defined, the pedestrian areas that approach a flight of steps should also be designed to make people aware of their presence. Hazard warning tactile slabs must be used at the approach and their colour should contrast with the surrounding paving.
In England, Approved Document M of the building regulations, entitled ‘Access to and use of buildings’, references light reflectance values when it defines the term ‘contrast visually’ within the document. Approved Document M states that, when describing stepped access, ‘People should be able to easily appreciate where to place their feet by highlighting nosings.’
Wales has its version of Parts M and Scottish building regulations cover the topic in Section 4.3 of the non-domestic Technical Handbook. Northern Ireland does so in Part H ‘Stairs, ramps, guarding and protection from impact’. In the Republic of Ireland, ‘Access and Use’ regulations can be found in Technical Guidance Document M.
The UK building regulations need to ensure that they tie in with the legislative requirements found in the Equality Act 2010. This act states that all new and refurbished public buildings and workplaces must ensure that safe entry, exit, and passage through the building is available to all, regardless of their disability, age, or gender.
Supporting advice for specifiers is given by the standard BS 8300:2018 ‘Design of an accessible and inclusive built environment’. It states that to meet the access needs of people with visual impairments there must be adequate visual contrast between building surfaces. This is a clear reference for the need to establish light reflectance values when selecting construction products, such as step slabs in the public realm.
Other considerations can affect the safety of those using steps in the public realm.
The minimum and maximum dimensions of the steps and risers are defined within building regulations. The dimensions must be consistent, and the risers closed, to help reduce the risk of people getting their feet, or walking aids, caught between the steps.
The materials used for steps in the public realm should not present a slip hazard when dry or wet. There is a test standard, BS 7976-2:2002, that can be used to measure slip resistance. Nosing that achieves a pendulum test value higher than 35 can be classified as low risk. Tobermore’s granite aggregate step unit, as well as the granite effect step slabs and risers in the Mayfair range, exceed this with a PTV over 45.
Using tactile paving is referenced within the building regulations as a means of providing information to visually impaired people to help them identify access routes and potential hazards. These should be used at the top and bottom of a flight of steps.
Available with contrasting nosing to ensure suitable light reflectance values (LRVs), our step slabs and risers are ideal for inclusive and aesthetically pleasing public spaces.
At Tobermore, we produce a range of step slabs, step units, and tactile paving slabs that are widely specified for use in public realm spaces.
Regarding the importance of providing light reflectance values for specifiers, Craig McBride, Tobermore’s Technical and Product Training Manager, comments:
“We use resilient and hard-wearing contrasting nosing strips on our step flags and step units. They are fully tested, and we publish their light reflectance values along with a raft of other product data. Our customers can specify our step slabs and step units with the confidence that they will be creating safe and robust access steps in public realm spaces.”
Our product selector makes finding the right product for your LRV requirements easy. Simply adjust the LRV slider on the product selector page and filter our range according to your project’s LRV needs.
To find out more about light reflectance values, and other useful insights when specifying steps in public realm spaces, you can request our Steps CPD, or for more information, you can contact our technical team who will be pleased to help.
Our HLP service is designed to simplify your decision making process by offering tailored solutions for your specific project needs.