Driveway design confirms your entry and exit points are safe and compliant for every vehicle expected to use them — and gradient is where most sloped-site designs fail, usually because the transitions weren't calculated properly.
Core gradient rules (AS 2890.1)
Maximum grade within the property: 1 in 4 (25%)
Maximum grade at the property line or footpath crossing: 1 in 20 (5%), extending 6m into the site to protect sightlines
Transitions required wherever a grade change exceeds 1 in 8 (12.5%) — minimum 2m long, at roughly half the difference between the two grades, preventing underside scraping at summits and sags
Design vehicles modelled at 120mm ground clearance to verify the full swept path stays clear
Engineering for steep sites
Switchbacks — horizontal curves that extend travel distance to bring the effective grade back under 1 in 4
Flat landing zones — required top and bottom, maximum 1 in 20, giving vehicles a safe pause point before entering traffic
Swept path verification — confirms longer vehicles clear the inner kerb and stay off opposing lanes on curved layouts
Surface selection — solid, textured surfaces on steeper grades for wet-weather traction; loose gravel isn't suitable
What council wants to see
Longitudinal sections showing existing versus proposed levels, cross-sections at the property boundary and garage entry, and formal certification confirming ground clearance holds throughout.
How the engagement moves
From enquiry to controlled issue- Step 01Send the project
Provide the site, available drawings and the issue that needs resolving.
- Step 02Confirm the scope
We identify the required assessment, documentation, programme and fee.
- Step 03Assess and coordinate
The technical work is developed against the project and authority requirements.
- Step 04Check and issue
The agreed review is completed before controlled issue and support through comments.
Common questions
What's the steepest a driveway can be?
1 in 4 (25%) within the property, dropping to 1 in 20 (5%) for the first 6m at the street.
How do you stop vehicles scraping on a steep driveway?
Transition grades — at least 2m long, roughly half the main slope — at every point where the grade change exceeds 1 in 8.
Does this apply to single residential driveways too?
Yes — AS 2890.1 governs all off-street driveway design, including houses on steep or constrained sites.
What if full compliance genuinely isn't achievable on my site?
Councils can accept a “Performance Solution” — a more detailed engineering case proving an alternative design is still safe and functional.
Send us the drawings. We'll tell you what you need.
2. Plans, if they exist
3. A description of the works
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