Accessible
Design Guide
Navigate AS 1428.1:2021 and NCC access requirements across residential, commercial and public building classes.
About this guide
AS 1428.1:2021 is the current Australian standard for accessible building design, referenced by NCC 2022 Amendment 2 as the DTS compliance pathway for new building work. It applies to existing buildings only where altered, extended, or subject to a change of use that triggers NCC compliance.
This guide summarises the standard's key requirements by element type, with reference clauses, critical dimensions, and notes on where designers most commonly fall short. It is not a substitute for the standard itself — always read the relevant clause in full and confirm the applicable NCC edition with your Registered Building Surveyor.
Heritage note. Where accessibility works affect heritage fabric, document the significance of affected elements and assess whether a Performance Solution is more appropriate than full DTS compliance. Performance Solutions must be prepared by a suitably qualified practitioner and accepted by the RBS.
Standard status & suite
AS 1428.1:2021 sits within a suite of accessibility standards. Understanding which standard applies to which element avoids specification errors.
Requirements by element
An accessible path of travel must be continuous, unobstructed, and connect all areas of the building required to be accessible under NCC Section D. The path encompasses every element along the route — external approaches, entries, corridors, lobbies, and vertical circulation.
Gradient is the most common design error. Any longitudinal gradient steeper than 1:20 triggers ramp requirements. Cross-falls above 1:40 cause instability for wheelchair users and are non-compliant.
Common design error. Designers frequently set a 1000mm corridor width and then position fire extinguisher brackets, signage, or door hardware within the clear zone — reducing actual clear width below 1000mm. Model all fixtures in the accessibility zone.
Ramps are the primary means of accessible grade change between levels. The standard distinguishes between general ramps (1:14 maximum) and threshold ramps (1:8 maximum, door threshold only). Threshold ramps are not a shortcut for general circulation — they apply only at doorways with a maximum 35mm rise.
Landings are required at the top, bottom, and at every point where the cumulative rise reaches 190mm. Positioning landings to clear door swing is a common coordination failure.
Design coordination note. A 190mm rise per flight at 1:14 gradient requires 2660mm of ramp run plus two 1200mm landings — minimum 5060mm total length. Model this early. Short-run ramps on tight sites frequently require a Performance Solution.
Accessible stairs supplement ramps and lifts — they do not replace them. The requirements apply to stairs on accessible paths of travel and exist primarily to assist ambulant users, including those with vision impairment.
Uniformity is critical. Mixed riser heights or going lengths within a flight are not permitted. Nosings must contrast visually without projecting — overhanging nosings are a trip hazard and non-compliant.
Handrails are required on both sides of all accessible ramps and stairs. The extension requirements at top and bottom are not optional and require coordination with landings, doorways, and wall returns.
Profile is frequently misspecified. A 50mm square hollow section with sharp edges is not a graspable handrail. Verify proprietary profiles against Cl. 9.5 before specifying.
Common specification issue. Horizontal extension requirements at top and bottom are frequently omitted from drawings. Annotate extensions explicitly — do not leave them to the contractor's interpretation of the standard.
Door requirements cover clear opening width, approach and latch-side circulation space, hardware type and height, opening force, threshold level, and glazing manifestation. All must be satisfied simultaneously — a door can pass the width test and fail on circulation space.
Clear opening width is measured with the door held at 90 degrees open. For a 90mm frame rebate and 40mm door thickness, a 1000mm doorset may deliver only 855mm clear. Always calculate from the schedule, not the nominal doorset size.
Design coordination. The 500mm latch-side clearance and the 760mm pull-side approach frequently conflict with corridor widths at narrow doorways. Plan door positions to allow both requirements to be met without exceeding corridor width.
TGSIs provide ground-level information for people with vision impairment. There are two types: hazard indicators (truncated domes — warn of an approaching hazard) and directional indicators (elongated bars — guide travel along a path). They are not interchangeable.
Luminance contrast between the TGSI and the adjacent surface is as important as physical placement. A 30% minimum LRV difference must be verified — calculate from manufacturer data, not photographic simulation.
Room identification signs must be mounted on the approach side, adjacent to the latch side of the door. Signs mounted on the door face or the wrong side of the frame are non-compliant.
The International Symbol of Access (ISA) must be displayed at all designated accessible elements. It must be reproduced to the specified proportions — rescaled or freehand versions are not acceptable.
Specification note. Specify signage substrates and finishes by LRV value, not by colour name or code. LRV is the measurable and defensible metric — colour appearance varies by finish and lighting conditions.
The accessible sanitary facility requires careful spatial coordination. The minimum room dimensions must accommodate the pan, basin, turning circle, and door swing simultaneously — which is rarely achieved without a detailed layout drawing cross-referenced against the standard's dimensioned diagrams (Cl. 17, Figures 22–26).
Two transfer configurations exist: left-hand transfer and right-hand transfer. Where only one unisex accessible facility is provided, base the configuration on the most likely user cohort or consult with an access consultant.
Design note. The 1900 × 1900mm minimum does not accommodate a full turning circle, a separate basin, and an outward-opening door without careful layout work. Always produce a dimensioned 1:20 layout drawing and overlay the 1800mm turning circle before issuing for permit.
Ambulant facilities serve users who can stand and walk but have limited mobility or balance — including people using crutches, walking frames, or with lower limb impairment. They are not an alternative to the wheelchair-accessible facility.
NCC D3.15 requires at least one ambulant cubicle wherever a sanitary facility has three or more cubicles. This is a frequently missed trigger in multi-cubicle amenity blocks.
Accessible parking spaces must be connected to the building by an accessible path of travel. The path from the bay to the accessible entry must itself comply with AS 1428.1 in full — including width, gradient, and surface requirements. Simply providing a compliant bay without a compliant path is a common and fundamental design failure.
NCC cross-reference
AS 1428.1 provides the technical dimensions. NCC Section D determines which building classes and areas must be accessible. Always read both together — the NCC sets the scope; AS 1428.1 sets the method.
NCC edition. Confirm with your RBS which NCC edition applies to the building permit. NCC 2022 Amendment 2 references AS 1428.1:2021 as the DTS standard (operative 29 July 2025). Projects with permits issued under earlier editions may reference AS 1428.1:2009. Do not assume the current edition applies to all active projects.
Plico Advisory
Need a formal review?
This guide is a general design reference. For projects requiring a formal accessibility compliance report, shop drawing review against AS 1428.1:2021, or a Performance Solution for heritage buildings, Plico offers advisory services scoped to your project stage.
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