Accessible sanitary facilities in accordance with AS 1428.1 (2021) are designed to accommodate independent use by people with disability, including wheelchair users, through the provision of sufficient circulation space, clearances to fixtures, and the coordinated positioning of fittings such as grabrails, pan, basin and door. The Standard establishes a minimum circulation space of 2300mm long x 1900mm wide, together with a defined 'Exclusion Zone' around the toilet pan. This approach provides sufficient clearances for the 90th percentile of wheelchair sizes, adjacent to and in front of the pan, enabling a wheelchair user to enter, turn, align, and transfer safely.
These dimensions are not arbitrary; they are based on the spatial requirements of a wheelchair and the functional movements associated with side transfer, forward approach and assisted use where required. Maintaining these clearances is essential to achieving the intended level of accessibility, independence, and dignity.
In existing buildings, however, site constraints such as structural walls, services, or building cores can limit the ability to achieve full compliance without significant and disproportionate works. In such cases, it is not uncommon for a minor reduction to one or more prescribed clearances to arise where walls cannot be relocated. In fact, the Premises Standards Section 4.5 provides a concession to accept the spatial requirements of a previous version of AS 1428.1 (2001), accepting a 2000mm long x 1600mm wide toilet pan circulation space.
In existing conditions, a reduction in a nominal dimension does not, in itself, determine non-compliance. The key consideration is whether the facility continues to provide effective circulation and functional usability for the intended user group. This includes assessing whether a wheelchair user can still enter the space, perform a turning movement (or equivalent manoeuvre), position adjacent to the pan, and utilise the grabrails and fixtures as intended.
Where these outcomes can be demonstrated, a Performance Solution may be appropriate, supported by a reasoned assessment that the impact of the reduced dimension is negligible in practice. This typically involves consideration of the extent and location of the reduction, alternative circulation paths, and the overall usability of the room. This approach would consider the Premises Standards concession.
The goal is to ensure, despite existing constraints, that the facility continues to provide safe, dignified access that is functionally equivalent to what AS 1428.1 envisages.
We can help develop this approach and document the Performance Solution.