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Retaining wall height, engineering and approval in NSW

In NSW, only a small retaining wall can be built without approval, and only when it also meets the other exempt-development conditions. Under the state's exempt and complying development code a retaining wall is generally exempt only up to 600 millimetres in height, with further conditions on distance from boundaries, drainage and what the wall supports. Anything higher, or anything that fails those conditions, needs approval through a complying development certificate or a development application, and it will need an engineer's design. Above about a metre, or where the wall carries a driveway, slab or building, engineering is unavoidable whatever the approval path. The practical rule: if the wall is more than knee-high, near a boundary, or holding up anything but a garden, plan for engineering and certification from the start. We design and certify walls as part of the job, so the approval paperwork is ready when the wall is.

Exempt, complying or development application

Exempt development needs no approval but has strict limits. Complying development is a fast-track approval issued by a certifier when the wall meets the code. Anything else goes to council as a development application. The height, the location relative to boundaries and buildings, and what the wall supports decide which path applies. Always check the current code text and your council's requirements; the limits are specific and they are enforced.

What the engineer does

The engineer designs the wall for the soil, the height and the surcharge: section, footing, drainage, geogrid or steel. At the end they inspect and certify that the wall was built to the design. That certificate is what the council or certifier wants, and it is what protects the owner if the ground ever moves.

Have this ready before you build

A survey or site plan showing boundaries and levels, a geotechnical report if the wall is significant, and a clear statement of what will sit above and below the wall. With those we can design, price and programme the wall in one pass.

Questions we are asked

Do I need approval for a 1 metre retaining wall in NSW?
Almost always, yes. A metre is above the exempt-development limit, so the wall needs a complying development certificate or a development application, and an engineer's design.
Who certifies the retaining wall?
The structural engineer who designed it inspects it during construction and issues a certificate on completion. We arrange that as part of the job.

Specifying a wall?
We will help.

Send the drawings or describe the site. We recommend a system and price it, with the certification included.

(02) 9344 9168
UCBC retaining wall site