Do all retaining walls need council approval or a geotechnical report?
Not every retaining wall follows the same approval pathway, and wall height alone does not universally determine whether approval, structural design or a geotechnical report is required. Relevant considerations can include the site, location, proposed works, boundaries, drainage, adjacent structures and applicable planning controls.
Council, certifier and project-designer requirements vary with the individual development. Obtain the actual written request or relevant project advice rather than relying on a broad rule that all walls over a particular height need the same documentation.
When ground assessment may help retaining-wall design
Ground-related considerations may include foundation bearing, fill, slope geometry, excavation, drainage, groundwater, nearby loads and neighbouring structures. The relevance of each factor depends on the specific wall and site.
Geotechnical information can support the structural designer's assessment of retaining conditions, but a geotechnical report is not automatically the complete retaining-wall structural design. The agreed scope should identify which engineering questions are being addressed.
Prepare the right documents before requesting a quote
Send the site address, wall layout, proposed height, available structural or architectural drawings, boundary information and the original council, certifier or engineer request. Photographs of existing slopes, cut, fill and drainage can also help.
The appropriate scope should reflect the actual development and local approval circumstances rather than an assumed council requirement.
Common questions
Retaining-wall approvals and ground risks: common questions
Does every retaining wall over one metre require a geotechnical report?+
There is no universal rule that every wall above a particular height needs the same report. Requirements depend on the development, site conditions, relevant planning controls and the applicable approval or design authority.
Is a retaining-wall geotechnical report the same as structural design?+
No. A geotechnical assessment can provide relevant ground information, while structural wall design is undertaken by the appropriately engaged designer.
What should I give the geotechnical consultant?+
Provide the site address, wall drawings, proposed height, boundary information, site photographs and the original request from your council, certifier or structural engineer.
Need Request retaining-wall geotechnical advice in Sydney?
Get a scope matched to the project
Send the site address, proposed works, current plans and any request from your builder, engineer, council or certifier. Sydney Geotechnical will review the information and confirm an appropriate scope and fee.
This guide provides general information only and is not a substitute for investigation, engineering advice, footing design or approval advice for a particular property. Project requirements and ground conditions must be assessed site by site.
