House Ramp Gradients: Choose the Right NCC Path

Identify the ramp before choosing a slope

A house can have different kinds of ramp. Check the building class and what the ramp is for. Check the code edition and state rules too. A single gradient does not cover every ramp, path or driveway.

This guide cites NCC 2022 and the 2022 Livable Housing Design Standard, version 1.3. Confirm the edition that applies to your project. Do not treat these citations as a review of a later edition.

Ordinary house ramps

Housing Provisions 11.2.3 covers ramps inside a building and external ramps serving an external doorway. The normal slope limit is 1:8. The ramp must carry the design loads. It needs landings at each end and no more than 15 m apart.

The note directs external ramps used for Livable Housing compliance to that standard. Do not use the ordinary 1:8 limit to design that access path.

The Livable Housing access path

Livable Housing Design Standard 2022 v1.3, clause 1.1 sets a 1:14 maximum gradient and 1:40 maximum crossfall for the step-free path. It requires at least 1000 mm width. Scope and exemptions must be checked first.

For ramping, its length limit is aggregate length, excluding landings:

• 9 m at 1:14.
• 15 m at 1:20.
• Linear interpolation between those gradients.

Adding landings does not restart that allowance. Each ramp end needs a landing at least 1200 mm long and at least the ramp width. The landing is level, or no steeper than 1:40 where needed for drainage.

The standard permits one step ramp within its stated limits. Read clause 1.1(5) for the complete detail. Do not mix its dimensions with another ramp type.

A geometry example

A chosen 1:14 slope with 500 mm rise needs 7000 mm horizontal run:

500 × 14 = 7000 mm = 7 m.

That is a length calculation. Add the required landings and check the whole access path, width, surfaces, barriers, drainage and door detail. A single passing dimension does not establish compliance.

Other building classes

Access routes in Class 2–9 buildings use other rules. These include Volume One Part D4 and the standards it calls up. Get the required design for that building. This house example does not size those ramps or landings.

Sources and related checks

• NCC Housing Provisions Part 11.2.
• ABCB Livable Housing Design Standard.
• Australian code hub and state links.
• Gradient conversion tool.