State Environmental Planning Policy (Housing) 2021

Excavation for the purposes of group homes must not exceed a maximum depth, measured from ground level (existing), of—

if located not more than 1m from any boundary—1m, and

if located more than 1m but not more than 1.5m from any boundary—2m, and

if located more than 1.5m from any boundary—3m.

Excavation for the purposes of a pier in a pier and beam foundation may exceed the maximum depth specified in subsection (1) if a professional engineer has certified the depth of the excavation.

Despite subsections (1) and (2), the excavation must not exceed a maximum depth, measured from ground level (existing), of 1m if the land is identified as Class 3 or 4 on an Acid Sulfate Soils Map or is within 40m of a waterbody (natural).

Fill must not exceed a maximum height, measured from ground level (existing), of 1m.

Despite subsection (4), the height of fill is not limited if the fill is contained—

wholly within the footprint of a group home, attached development or detached development, or

by a drop edge beam.

Fill that is higher than 150mm above ground level (existing) and is not contained wholly within the footprint of a group home or any attached development or detached development is limited to 50% of the landscaped area of the lot.

The ground level (finished) of the fill must not be used to measure the height of any group home or any attached development or detached development under this code.

Support for earthworks more than 600mm above or below ground level (existing) must take the form of a retaining wall or other structural support that—

a professional engineer has certified as structurally sound, including in relation to, but not limited to, the ability to withstand the forces of lateral soil load, and

has been designed so as not to redirect the flow of any surface water or ground water, or cause sediment to be transported, onto an adjoining property, and

has adequate drainage lines connected to the stormwater drainage system for the site, and

does not have a total height measured vertically from the base of the retaining wall or structural support to its uppermost portion that is more than the height of the associated excavation or fill, and

is separated from any other retaining wall or structural support on the site by at least 2m, measured horizontally, and

has been installed in accordance with any manufacturer’s specifications, and

if it is an embankment or batter—has a toe or top that is more than 1m from any side or rear boundary.