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Specular Inclusive vs Specular Exclusive for Luminance Contrast

Measurement methods when testing for luminance contrast – Specular Inclusive vs Exclusive

Specular Inclusive vs Specular Exclusive for Luminance Contrast TestsMost people with blindness or vision impairment still have some form of vision. This is why sufficient luminance contrast of building materials benefits people with vision impairment, and in fact, all pedestrians. The method of testing luminance contrast is to measure the light reflected from one surface and comparing it to the light reflected from another surface. Testing can only be conducted using specialised equipment. 

When testing the contrast ratio of surfaces for compliance under Australian Standards AS 1428.1 & AS 1428.4.1 it is essential that the correct geometric equipment is used by the testing company. This is to ensure correct results are obtained, and to reduce the risk of future litigation should a case be brought before the court. 

When shopping around for a company to conduct luminance contrast testing for your building materials, be careful, as not all testing companies use compliant equipment. For more information on what equipment should be used see the blog on our website https://www.disabilityaccessconsultants.com.au/luminance-contrast-equipment-equations/ 

Even though the testing equipment used may be compliant, what is not mentioned in the Australian Standards and is of great significance in terms of luminance contrast is Specular Inclusive and Exclusive measurements. Compliant equipment used for luminance contrast testing relies on one particular method of measurement: specular inclusive. 

Luminance Contrast Tests Specular Inclusive vs Specular ExclusiveThe word specular refers to the reflectiveness of a surface, much like a mirror. When light rays bounce off a glossy or shiny surface, most of those rays bounce back and hit the eye, making a surface appear more saturated in colour. However, some rays will scatter in different directions, and some will be absorbed by the material itself and not reflect off the surface at all. More rays reflected mean a brighter colour appearance. More rays scattered mean a duller colour appearance.  

So, what determines which rays are reflected and which are scattered? It comes down to the texture and glossiness of the surface. A smooth shiny surface will reflect more light, and a rough matt surface will scatter more light. For example, a glossy yellow sample will appear more vivid to the naked eye as opposed to sanded yellow sample. Why does it matter? Yellow is yellow right? Well, yes, to some degree. This is why current compliant testing equipment use a Specular inclusive measurement mode, which captures the true colour of a material regardless of its surface finish. This is achieved by “including” both reflected and scattered light when measuring.  

Specular inclusive testing is seen as the best way to test for luminance reflection because it removes any variances of the surfaces condition. So, if we tested the glossy yellow sample and the sanded yellow sample using a specular inclusive mode, we would get the same colour value on both samples, meaning they are the “same”. 

However, we already know that the surface finish of a material, glossy vs matt, affects the way a colour appears to the naked eye. And the best way to test the visual appearance of material’s colour is by the specular exclusive mode. This mode does not consider how many light rays are reflected off the surface, making it more sensitive to the finished texture. If we take the previous example of a glossy yellow sample vs a sanded yellow sample, a specular exclusive measurement will return different results or colour values for each sample, meaning they are “different”, which indeed they appear to be. 

Which is better Specular Inclusive vs Specular Exclusive for luminance contrast testingSo which method is best? Well, it comes down to equipment. The tristimulus colourimeter or spectrophotometer with a diffuse illumination/normal viewing (d/o) geometry with CIE Standard Illuminant D65 is the only equipment specified by the Australian Standards to test luminance contrast (AS 1428.1 – 2009 & AS 1428.4.1 – 2009). This equipment only offers the one measuring mode, specular inclusive, to test colour values of materials.  

If appearance measurements are required, then the specular exclusive mode offered by Photometer tests can be performed (Note that these are affected by ambient light). Laboratory tests by Equal Access are Specular Inclusive. 

Is gender specified signage in sanitary facilities required?

F2.4 Accessible Sanitary Facilities
In a building required to be accessible –

The above reference from the 2016 National Construction Code (NCC) Volume One of the Building Code of Australia (BCA), instructs the provision of hygiene facilities fit for use by males and females with disability. The BCA is specific in assigning all accessible sanitary facilities, and in some cases, general facilities, as unisex. In fact, the word ‘unisex’ is mentioned 39 times in the current NCC Volume One of the BCA, mostly when referring to accessible toilets.

The promotion of accessible sanitary facilities for both males and females may be seen as a more equitable and fair provision of toilets, which is, according to the Australian Standards 1428.2-1992, designed for use by people with disabilities who are accompanied by a carer of the opposite sex. However, what happens when the person with disability does not identify themselves as either gender? Or, perhaps, their carer doesn’t either?

People who identify outside of a gender binary can be seen as discriminated against where only male, female, or unisex facilities are available. See a similar article here: https://www.disabilityaccessconsultants.com.au/cant-unisex-ambulant-toilet/

SDA Specialist Disability Accommodation Under The NDIS

Equal Access disbaility access consultants undertake specialised SDA Specialist Disability Accommodation Assessments in accordance with the requirements of the NDIS and NDIA throughout Australia.

Specialist Disability Accommodation (SDA) refers accommodation for participants who are eligible for specialist housing solutions to assist with the delivery of environmental supports to cater for their significant functional impairment and/or meet their very high (support) needs. SDA refers to the homes in which support services are delivered, and may include specific designs for people with very high needs or may be located as such for viable provision of high level support and care to facilitate independent living.

From 1 July 2016, SDA will be funded by the National Disability Insurance Scheme (NDIS; Scheme), with an aim to enable people with disability to have greater choice and control over support services and housing facilities. In Metropolitan Melbourne, the NDIS rollout has already begun in the North East, due to be followed by other districts from 1 November 2017.

How the NDIA determines who is eligible

The NDIA will determine which NDIS participants will benefit from specialist disability accommodation, by conducting various assessments with references to two sets of criteria:

Why Can’t I Have A Unisex Ambulant Toilet?

A unisex toilet is a public toilet designed to be suitable for use by both males and females, and is now often extended for use by persons of any gender, which benefits population groups who identify themselves as any identity outside the boundaries of male/female.

Here at Equal Access we often receive inquiries as to why new developments or upgrade works have triggered the required provision of single gender ambulant toilets.

Adult with an ambulant disability using crutches

Adult with an ambulant disability using crutches

Changes to the 2016 National Construction Code (NCC) Volume 1 of the Building Code of Australia (BCA) has incorporated an amendment to Part F2 Sanitary and Other Facilities. The new change, specifically Clause F2.3(a), instructs the provision of separate sanitary facilities for males and females, with minimal exceptions. The provision of unisex accessible sanitary compartments (and showers) is one exception, which was also mandated in the now superseded 2015 NCC.

To acquire an understanding of why the Victorian Building Authority promotes and regulates the provision of unisex accessible toilets we may find insight in AS 1428.2-1992, where Clause 15 regarding Sanitary Facilities notes a unisex toilet is recommended for general use by the public where a person with a disability may be accompanied by a member of the opposite sex (a carer for example).