Pre-purchase Geotechnical Due Diligence
Understand the ground conditions before you buy.
Ground conditions can influence what you can build, the foundations you may need and the complexity of developing a property. Our pre-purchase assessments help you understand potential constraints, their implications and what may need further investigation before you commit.
Request a Pre-purchase AssessmentWhen a Pre-purchase Assessment can help
Whether you are buying vacant land or an existing property, a geotechnical assessment can help you understand ground-related issues that may affect your plans.
It is particularly useful when:
- The property is steep, near a slope or has a history of ground movement.
- You are considering a new home, extension, basement, pool or substantial earthworks.
- Existing retaining walls, cut slopes, filled areas or drainage conditions raise questions.
- Previous reports identify ground constraints or recommend further investigation.
- The property is unsewered and future development will need onsite wastewater management.
- You want to understand potential foundation and earthworks implications before purchasing.
The assessment is tailored to the property, your intended use and the information available.
What we review
Our desktop assessment brings together available records, mapping and aerial imagery to develop an initial understanding of the site.
| Assessment topic | What we consider |
|---|---|
| Geology and ground conditions | Mapped geology, available investigation records and the soil and rock conditions likely to occur beneath the property. |
| Groundwater | Available groundwater records, likely groundwater conditions and indicative depth where the evidence supports an estimate. |
| Terrain and slope | Site gradients, surrounding landforms and their implications for development and access. |
| Landslip history | Recorded landslips, mapped susceptibility and evidence of previous movement in available reports and imagery. |
| Aerial imagery and site history | Current and historical imagery, including MetroMap where available, to identify changes in land use, vegetation, earthworks and drainage. |
| Climate and drainage context | Rainfall patterns and seasonal conditions relevant to ground moisture, drainage and onsite wastewater management. |
| Onsite wastewater considerations | Available soil information and the likely soil category, where supported, to identify preliminary implications for onsite wastewater management options. |
Desktop findings depend on the coverage, age and quality of available information. We identify significant gaps and distinguish recorded information from our engineering interpretation.
Choose the appropriate level of assessment
Desktop assessment
A review of available mapping, imagery, property information and relevant reports, without visiting the site.
We discuss what the available evidence suggests about ground conditions and their implications for your proposed development. This may include indicative site classification, possible foundation options, excavation and earthworks considerations, slope constraints and matters requiring further investigation.
This option provides an initial assessment when you need to understand potential issues before deciding whether more detailed work is warranted.
Desktop assessment and site walkover
Includes the desktop assessment, together with a site visit to assess accessible, visible conditions.
The walkover considers existing cuts and fills, vegetation cover, surface drainage, seepage, erosion, retaining structures and visible signs of instability. Observations are used to refine the desktop interpretation and identify concerns that may not be apparent from records or imagery.
Access must be arranged with the property owner or their authorised representative. A walkover does not establish conditions below ground.
Assessment with intrusive investigation
Adds a ground investigation scoped specifically for the property, proposed development and questions requiring resolution.
The investigation may include boreholes, dynamic cone penetrometer testing, sampling and laboratory testing where appropriate. The locations, depths and testing requirements are determined for each project.
This option provides direct information about the ground conditions investigated and supports more detailed advice within the proposed scope.
What the findings mean for your plans
We explain how the findings may influence:
- The location and arrangement of proposed development
- Likely foundation options and the need for further site classification or design work
- Excavation, rock removal, cut and fill, and retaining requirements
- Slope stability, drainage and groundwater management
- Preliminary onsite wastewater management considerations
- Construction complexity and matters that may affect the project budget
Where information is insufficient to reach a reliable conclusion, we explain the uncertainty and the additional work that would help resolve it.
What you receive
A written report proportionate to your selected assessment level, setting out:
- The information reviewed and any inspection or investigation completed
- Relevant maps and imagery, together with site observations where a site visit is included
- Key findings and their implications for your intended use
- Important uncertainties and limitations
- Recommended further investigations or specialist assessments
Desktop estimates of site classification, foundation options, groundwater depth and wastewater soil category are preliminary. Formal site classification, design recommendations and assessments required for approval are provided only where included in our proposed scope.
Getting started
Send us the property address or listing, a brief description of your plans and any available geotechnical reports, drawings or relevant council correspondence.
Tell us your purchase deadline so we can confirm the appropriate scope and whether we can meet your timing. Where a site visit or intrusive investigation is proposed, we will confirm access requirements before proceeding.
Considering a property purchase?
Send us the property details and your proposed use. We will help identify the assessment level suited to your questions and provide a quotation.