When it comes to designing accessible environments, the gradient of ramps is a critical consideration. In Australia a ramp is required to have a 1 in 14 gradient for a maximum length of 9m before a landing is required as outlined in AS1428.1-2009.

In New Zealand, NZS4121:2001 allows ramps with a maximum gradient of 1 in 12.

But why is the New Zealand steeper ramp grade considered acceptable, especially for people using wheelchairs or mobility aids? The answer lies in a combination of international alignment, practical usability, and design constraints unique to New Zealand’s built environment.

The 1:12 gradient is not unique to New Zealand. It aligns with many global accessibility standards. Across these codes, 1 in 12 is generally regarded as the steepest slope that can still be safely and independently used by most people in manual wheelchairs provided the ramp is short and includes appropriate landings and handrails.

For many users, particularly those with strong upper body strength or powered mobility devices, a 1:12 ramp is manageable. It also works for people using walking frames or crutches. That said, NZS 4121 requires 1 in 12 ramps for a maximum length of 9m before a landing is required, handrails on both sides, kerbrails, and slip resistant surfaces. These requirements ensure that ramps remain usable and safe, even at steeper gradients.