Luminance Contrast

Luminance Contrast

Luminance contrast is defined in the most current Australian Standard 1428.1-2021 as ‘the light reflected from one surface or component, compared to the light reflected from another surface or component’. 

In order to measure the luminance contrast, manufacturers test their products to obtain a LRV or luminance reflectance value. Values from adjacent materials (say, a stair nosing and the surrounding stair tread) are then run through a special formula to mathematically determine the contrast value.

If LRV information is not known for one or both of the surfaces, site testing is required to measure the contrast. There are numerous companies throughout Australia that can assist with LRV testing.

 

How much contrast is required for stair nosing?

Australian Standards AS 1428.1:2021 Design for access and mobility-General requirements for access - New building work specifies a minimum of 30% luminance contrast requirement between the stair nosing and the surrounding substrate colour. This assists all pedestrians, especially those with visual impairment, to safely navigate the edge of the step. Highlighting the nosing on steps is important for all stairs but stairs which are poorly lit e.g. (fire stairs and external stairs at night) are of significant danger to pedestrians. Safety Stride recommends that dimly stairs are also enhanced by the use of stair lights and other smart sensor lights that work in conjunction with the contrasting stair nosing.

Safety Stride can assist with recommendations with respect to luminance contrast. We also have luminance reflectance value (LRV) test reports for our products which show the amount of visible light the products reflect. This information allows architects and specifiers to make upfront calculations to ensure materials have been correctly selected in new projects. Please contact us today for technical assistance or LRV test reports on specific products.

 

Are their limits to the overall dimensions of stair nosing as required by AS 1428.1:2021?

Yes, In basic terms, a product with an area of contrast ranging between 50 - 75mm on the tread and not greater than 10mm on the riser, while offering a minimum of 30% contrast to the surrounds, is required. Nosing which are smaller or larger than these dimensions are therefore non-compliant if a strict interpretation of the standard is applied. Please note that this is a simplification and there are many other considerations and complexities to this area of building. We are here to help - please contact us for project specific assistance.

 

Why only 10mm on the front riser ?

We have literally had hundreds of people ask this question to us over the last decade. One reason for the short/10mm return at the front is that longer returns were found to be a potential trip hazard.

'Legacy' stair nosing which have noses/front returns longer than 10mm are still in circulation (we can still manufacture them), but they should only be used in certain circumstances and when permission has been expressly given by authorities / certifiers to do so.