Auckland project guide
Do I need consent for a retaining wall?
Auckland’s sloping sections make retaining walls a common project. Whether you need consent depends on how much ground the wall holds back and what sits above it.
When a retaining wall can be exempt
A retaining wall can be exempt from building consent if it retains no more than 1.5 m depth of ground and doesn’t support any extra load. Extra load, called surcharge, includes driveways, parked cars, buildings or a steep slope above the wall.
When you need consent
- It retains more than 1.5 m of ground
- A driveway, building, fence or slope sits above it
- It forms part of a larger project that needs consent
Don’t forget drainage
Water building up behind a wall is a common cause of failure. Plan drainage behind the wall and where that water will go. If you’re in an overland flow path or near a public stormwater pipe, check this early.
What your property can change
- Earthworks rules in your zone, which may need resource consent
- Land stability or erosion hazards recorded on your LIM
- Public pipes close to where you plan to dig
- Boundary walls, which may affect neighbours
Common questions
Who is responsible for a retaining wall on a boundary?
It depends on who built it and whose land it supports. Talk to your neighbour early and get advice if needed.
Do I need an engineer?
For walls that need consent, usually yes. Even for exempt walls, an engineer’s input is worth it on unstable or steep ground.