Compliance with AS3798 – Guidelines on Earthworks for Commercial and Residential Developments is essential for achieving stable ground, regulatory approval and long-term performance.
AS3798 provides a structured framework for planning, supervising, testing and certifying earthworks across residential, commercial and infrastructure projects.
This guide explains what AS3798 requires, how compliance is achieved and why independent geotechnical oversight is critical.
What Is AS3798?
AS3798 is the Australian Standard that sets out best-practice guidelines for earthworks associated with building and development projects.
The standard addresses:
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Earthworks planning and methodology
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Material assessment and suitability
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Compaction and moisture control
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Inspection and testing requirements
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Levels of geotechnical supervision
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Documentation and certification
AS3798 applies to both commercial and residential developments and is commonly referenced by councils, certifiers and project stakeholders.
Why AS3798 Compliance Matters
Non-compliant earthworks can result in:
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Ground settlement and structural damage
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Delays in approvals and certifications
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Increased remediation costs
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Long-term performance issues
AS3798 compliance provides confidence that earthworks are designed, executed and validated to support safe and durable construction outcomes.
Key Components of AS3798 Earthworks Compliance
1. Earthworks Planning and Site Preparation
AS3798 requires earthworks to be properly planned based on site conditions and project requirements.
This includes:
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Review of geotechnical investigations
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Identification of site constraints
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Development of an appropriate earthworks strategy
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Consideration of staging, drainage and material management
Early geotechnical involvement is essential to meeting these requirements.
2. Material Assessment and Classification
All materials used in earthworks must be assessed for suitability.
AS3798 requires:
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Classification of soils and aggregates
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Assessment of site-won and imported materials
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Identification of unsuitable or contaminated materials
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Verification of material reusability or treatment requirements
Laboratory testing such as PSD, MDD, CBR and soil reactivity assessments may be required to confirm material performance.
3. Compaction and Moisture Control
Proper compaction and moisture control are fundamental to compliant earthworks.
AS3798 specifies:
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Target compaction levels
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Moisture content requirements
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Compaction methods appropriate to material type
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Verification through field testing
On-site testing typically includes density testing, moisture content measurement and proof-roll assessments.
4. Inspection, Testing and Supervision Levels
AS3798 defines two levels of earthworks supervision:
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Level 1 Supervision for low-risk, uniform sites
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Level 2 Supervision for sites with higher variability or complexity
The required level of supervision is determined by a geotechnical engineer based on site risk, material variability and earthworks extent.
Independent supervision ensures that earthworks are executed in accordance with design intent and standard requirements.
5. Documentation and Certification
A critical component of AS3798 compliance is clear and complete documentation.
AS3798-compliant reporting typically includes:
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Compaction and density test results
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Laboratory testing data (CBR, MDD, PSD)
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Material classifications (VENM / ENM where applicable)
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Records of inspections and testing locations
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Level 1 or Level 2 certification
Certification confirms that earthworks meet the requirements of AS3798 and are suitable for construction to proceed.
Who Is Responsible for AS3798 Compliance?
AS3798 compliance is a shared responsibility:
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Developers and builders must ensure appropriate geotechnical engagement
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Contractors must execute earthworks in accordance with specifications
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Geotechnical engineers must provide independent assessment, testing and certification
Clear roles and early engagement help prevent compliance gaps.
Common AS3798 Compliance Risks
Common issues that lead to non-compliance include:
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Inadequate geotechnical investigation
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Incorrect supervision level selection
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Insufficient compaction testing
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Poor moisture control
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Incomplete documentation
Independent geotechnical oversight helps identify and manage these risks early.
AS3798 Compliance with Ideal Geotech
Ideal Geotech provides independent geotechnical services to support AS3798-compliant earthworks, including:
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Earthworks planning support
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Material assessment and testing
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Level 1 and Level 2 supervision
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Field and laboratory testing
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Clear, contractor-ready reporting
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AS3798 certification
Our focus is on practical advice, timely reporting and compliant outcomes—helping projects move forward with confidence.
Need Help Navigating AS3798?
Understanding AS3798 requirements early can save time, cost and risk later in the project.
IdealGeotech works alongside project teams to deliver clear guidance, independent oversight and reliable certification—ensuring earthworks meet AS3798 requirements from start to finish.
