Geotechnical Project Scope Checklist for Builders, Structural Engineers and Certifiers

Start with the actual engineering or approval question

A useful geotechnical brief identifies the decision the report needs to support. A residential footing designer may require an AS 2870 site classification, while a larger development may need investigation of founding conditions, bearing, excavation, retaining structures, groundwater, slope or construction verification.

Avoid assuming that a standard soil report answers every design question. The required investigation locations, depths, methods and reporting deliverables should be proportionate to the proposed work and the particular site.

• Identify whether the brief concerns site classification, foundation design, retaining works, slope stability, earthworks, percolation or construction inspection.
• Provide the exact wording of any structural engineer, architect, builder, certifier or approval authority request.
• Confirm whether a specific report, site inspection, design parameter, field test or staged assessment has been requested.
• Identify any relevant project deadline without assuming a guaranteed reporting timeframe.

Provide the site identification and current project documents

Supply the property address, suburb and available lot details together with the current architectural drawings, site plan and survey. A proposed footprint, floor levels, cut and fill, retaining works and access information help determine where site observations or investigation points will be most useful.

Where structural drawings or footing concepts are available, include them with the relevant loading, basement, wall or excavation information. If documentation is preliminary, explain what remains undecided so the investigation can be scoped appropriately.

• Site address, suburb and available lot or deposited-plan information.
• Current architectural plans, proposed footprint and project description.
• Survey, levels, existing structures and significant trees or drainage features where available.
• Structural concept, footing requirements, basement or retaining-wall drawings where available.
• Site access photographs, gates, stairs, overhead constraints and equipment-access limitations.
• Existing geotechnical reports, site-history information or previous earthworks records if relevant.

Highlight project-specific ground and construction risks

Potential site constraints should be identified early rather than discovered after a generic scope has been issued. Relevant issues can include placed fill, reactive clay, soft or wet ground, steep terrain, rock excavation, existing retaining walls, groundwater, nearby buildings and restricted access.

Different Sydney regions can present different geological contexts, but local mapping does not determine the actual profile or site classification of an individual property. The investigation should respond to the proposed development, site history and observed conditions.

• Proposed basement, significant excavation, shoring or boundary proximity.
• Sloping ground, existing movement, proposed cut or fill and retaining-wall geometry.
• Known or suspected fill, former structures, wet areas or drainage concerns.
• Specific foundation bearing, pavement, working-platform or compaction questions.
• Wastewater disposal, stormwater infiltration or groundwater-related investigation requests.
• Site security, utility clearance, underground services and safe field access.

Clarify council, certifier and designer requirements

A council or certifier request should be provided in its original wording rather than paraphrased as a generic geotechnical report. Requirements depend on the development, site circumstances and relevant approval pathway; there is no universal rule that every DA, CDC or retaining wall requires the same assessment.

Where the structural engineer has requested founding information, design parameters, excavation advice or construction-stage verification, include that specific brief. This helps align the investigation and report with the real design or approval decision.

Request a proportionate scope and quotation

Send the site address, current plans and specific engineering or approval request through Sydney Geotechnical's secure enquiry form. The appropriate scope can then be matched to the actual project rather than an assumed testing package.

Confirmed starting prices include residential site classification from $750, geotechnical investigations from $2,200, slope stability assessments from $1,500 and construction inspections from $450. The $750 starting price applies specifically to site classification; it should not be interpreted as the price for every soil test or geotechnical investigation.