The Importance of Contrasting Nosings on Stair Treads: A Key Component of Accessible Design
In Australia, ensuring accessibility in public and private buildings is a legal obligation defined by a series of regulations, including the Building Code of Australia 2022 and the Australian Standard AS 1428.1 (Generally buildings classified as Class 2-10 Buildings. Transport buildings are required to comply with the Disability Standards for Accessible Public Transport 2002, which will be addressed in a separate blog post). Among the various architectural elements that embody accessibility principles, contrasting nosings on stair treads play a pivotal role. This blog explores the necessity of incorporating contrasting nosings, particularly for people with vision impairment, alongside the implications this has for compliance, safety, and universal design.

Why Nosings Matter
Stairs pose a significant hazard in the built environment. For individuals with vision loss, detecting the edges of stair treads can be particularly challenging. This heightens the risk of falls and injuries, making it essential to provide clear visual cues. Contrasting nosings serve as an effective way to outline where stair treads end and help guide users safely up and down stairs.
Stair nosings not only enhance safety, but they also improve functionality by promoting confidence among users when navigating stairs.
The Role of Luminance Contrast
Luminance contrast is defined as the difference in light levels between two surfaces. According to Australian Standard AS 1428.1, stair nosing treads must possess a minimum luminance contrast of 30%. This specific requirement is crucial as it aids those with vision impairment in recognising where a stair tread ends, especially under low-light conditions, which are common in fire-isolated stairways.
The necessity of luminance contrast becomes clear when we consider how the human eye perceives brightness. For users with partial sight, especially those forming residual vision from conditions like glaucoma, strong luminance contrast can mean the difference between navigating safely and experiencing disorientation.
It’s important to note that while colour contrast can be valuable, it does not serve all users. Some individuals may not differentiate colours effectively; however, almost universally, luminance contrast can be distinguished. This makes it a more reliable option for increasing accessibility.


Dimensions Matter: A Thoughtful Approach
In accordance with AS 1428.1-2009, the tread nosing must have a width extending across the entire tread with a depth between 50-75mm. The guidance from the Australian Standards firmly supports this specification for several reasons:
1. Visibility: The minimum depth ensures that a notable portion of the nosing is visible to users, regardless of lighting conditions.
2. Functionality: If the depth exceeds 75mm, it may detract from the visible space of the tread itself, blending the nosing with the riser, especially when descending. Users can struggle to identify where one step ends and another begins, significantly affecting their ability to navigate safely.
3. Riser Considerations: The extension of the tread nosing should never exceed 10mm below the riser. If nosings descend beyond this limit, it complicates visibility by obscuring the top edge. A misjudgement here can lead to tripping hazards, making this specification particularly important for maintaining navigational clarity.

Avoiding Common Pitfalls
In the design of stair nosings and treads, certain materials and configurations should be avoided. For example, the inclusion of alternating metal strips can lead to visual blending, effectively disappearing from sight due to the “washing out” effect of the stair background.
When using materials such as inserted graphite or different types of aluminium, designers must ensure that they do not diminish the visibility that contrasting colours are supposed to convey. The principle is simple: the aim is to ensure that the target is always clear, allowing users with vision impairments to safely detect where the tread ends and the next begins.

The Opaque Riser Requirement
In practice, stair risers must be opaque to prevent strobing effects. This phenomenon can trigger disorientation or vertigo in individuals with vision impairments, leading to a significant risk of falls. Strobing occurs when light reflects off clear or shiny surfaces and flickers as users ascend or descend the stairs. For many visually impaired users, this strobing can have a disconcerting effect, making stair navigation challenging and even hazardous.
The Role of Assistance Animals
It’s equally important to consider the needs of assistance animals, such as guide dogs. Such animals depend on clear visual and tactile cues within the environment. Open risers or overly complex designs can hinder their ability to guide their owners safely up/down stairs. To foster a user-friendly experience for all, incorporating adequate in-fills for the risers is crucial.
Slip Resistance: Another Layer of Safety
As outlined in BCA Table D3D15, stair treads must meet specific slip-resistance classifications. An adequately textured surface encourages stability on both dry and wet conditions.

Why does slip resistance matter? In many cases, visually impaired individuals use tactile feedback and memory to navigate spaces. If a stair tread is slippery, even a small slip could result in a catastrophic fall, which is particularly dangerous for those with vision impairments as they may not have the same reflexes or awareness as sighted individuals.
When designing accessible stairways, it’s essential to evaluate environmental factors and ensure that materials selected for both treads and nosings provide adequate grip. It’s essential to maintain the surface quality over time as slip resistance can diminish due to wear and tear. Regular maintenance and inspections of stair surfaces should remain integral parts of facility management to ensure ongoing safety.
Improving Navigation with Clear Design Principles
To ensure that stair treads and their contrasting nosings adhere to best practices, designers and architects must keep several principles in mind:
- Consistency is Key: Uniformity in Design: All stair treads in a facility should maintain the same depth and luminance contrast. This consistency allows users to memorise the layout and anticipate each step without anxiety. Changes in depth or pattern can lead to confusion and should be avoided.
- Thoughtful Material Selection: Using materials that are non-slip while also being visually apparent allows individuals with low vision to feel secure when utilising stairs. Materials should not only bring safety but also reflect aesthetic considerations to maintain the overall design quality of the building.
- Training and Awareness: Understanding the needs of individuals with disabilities goes beyond visual appeal; it includes training employees and stakeholders on the importance of these adaptations. For instance, training maintenance teams to know the significance of preserving luminance contrast or assessing slip-resistant surfaces can meaningfully contribute to accessibility.
- Smart Lighting Solutions: Effective stairway lighting is paramount for enhancing the visibility of contrasting nosings. Smart lighting solutions that adjust to surrounding light conditions can be efficient in ensuring that stairways maintain visibility regardless of the time of day. Consideration of natural and artificial light sources can significantly impact user experience.
The Broader Implications of Accessible Design
Aside from compliance and risk reduction, implementing contrasting nosings and other accessibility features has implications for society as a whole:
- Civic Responsibility: A commitment to accessible design promotes social equity. When individuals are given the ability to navigate public spaces independently, it reflects a society that values all its members.
- Enhanced Community Engagement: Spaces designed with consideration for accessibility tend to attract a broader demographic, including tourists, locals, and community members. They become spaces where everyone feels welcomed and included.
- Improved User Experience: For anyone using a facility, whether they have a disability or not, clear signage, well-defined spaces, and navigable areas enhance overall satisfaction and comfort. This can positively impact community morale and productivity, especially in workplace environments.
- Economic Benefits: Increasing the accessibility of public and private buildings can lead to economic growth. When everyone can access facilities, businesses have the potential to increase their customer base, fostering revenue growth.
- Future-Proofing Design: As populations age, the demand for accessible infrastructure will only grow. Incorporating accessible design principles now prepares communities and organizations for future needs—making spaces functional for all.
Conclusion: A Step Toward Inclusivity
Understanding the need for contrasting nosings on stair treads is crucial for developing inclusive and accessible environments. The Building Code of Australia and Australian Standard AS 1428.1 provide clear standards that, when followed, significantly reduce the risks of falls, enhance navigation for those with vision impairment, and promote social equity across the nation.
Implementing these requirements not only fulfills a legal responsibility but cultivates a culture of inclusivity that benefits everyone in the community. From safety to user experience, the integration of well-designed contrasting nosings has profound implications for creating environments that invite all individuals to travel unhindered, embracing independence and safety within the architectural fabric of our society.
Contrasting nosings are not just simple architectural features; they are vital components of a comprehensive strategy to ensure that our stairways are as safe and welcoming as possible. By prioritizing accessible design, we take significant strides toward a society where everyone can navigate their built environments with confidence and ease. The responsibility begins with architects and builders, but it flourishes when communities uphold, celebrate, and foster inclusive practices. Together, we can make accessibility a fundamental truth in every design choice, forging pathways that truly accommodate all.
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