Soil Testing & Site Classification

Soil testing is one of the early site investigations that can influence design, construction planning, footing requirements, slab design, civil works and project cost.

For builders, developers, commercial property owners, architects, project managers and homeowners, a soil test or site classification report helps identify the ground conditions below the site before design decisions are finalised.

This matters because buildings, car parks, pavements, retaining walls and drainage systems all interact with the ground below them. If the soil conditions are not understood early, the project may face redesign, delays or unexpected construction issues.

For commercial and development projects, soil information can support better planning before the project moves too far into documentation or approval.

What is soil testing?

Soil testing involves investigating the ground conditions at a site to understand how the soil may behave under a proposed building or structure.

For residential projects, this commonly supports AS 2870 site classification for slabs and footings. For commercial, industrial and larger development projects, soil information may also help inform footing design, earthworks, pavement design, drainage, retaining walls and broader engineering coordination.

A soil test may assess the soil profile, soil type, reactivity, fill, moisture conditions, depth of layers, site disturbance and other factors that could affect construction.

The outcome is usually a soil report or site classification report that can be used by the structural engineer, builder, designer, developer or project team.

Why soil testing matters for commercial clients

Commercial projects often involve more than a simple building footprint.

A commercial development may include car parks, loading areas, access roads, stormwater infrastructure, retaining walls, slabs, pavements, service trenches, landscaping, plant areas and future expansion zones.

Each of these can be affected by soil conditions.

If the soil is reactive, soft, filled, variable, poorly drained or previously disturbed, it may influence the way the site is designed and built.

Early soil testing gives the project team better information before major design decisions are made. This helps reduce uncertainty for developers, builders, architects and commercial property owners.

What is an AS 2870 site classification report?

AS 2870 is the Australian Standard used for residential slabs and footings.

A site classification report provides information about expected ground movement at a residential site. This helps inform the footing and slab design.

While AS 2870 is most commonly associated with residential buildings, the broader principle still matters for commercial projects: the structure and the site conditions need to be understood together.

For commercial or industrial projects, the required investigation may be different depending on the project scale, building use, loading, site history and engineering requirements.

The important point is that soil information should be available before structural and civil design decisions are finalised.

How soil conditions affect design

Soil conditions can influence several parts of a project.

They can affect footing depth, slab design, site preparation, excavation, drainage, retaining wall design, pavement design and long-term building performance.

For example, reactive soils may move with moisture changes. Filled ground may need further assessment. Poor drainage may affect pavement or slab performance. Soft or variable soil may require a different design response.

These issues do not always stop a project from proceeding. But they do need to be understood early so the design can respond properly.

Why builders and developers need soil reports early

Builders and developers need reliable information before pricing, documentation and construction planning are locked in.

If soil testing is delayed, the structural engineer may not be able to finalise footing or slab design. Civil design may also be affected where site grading, drainage, retaining walls, pavements or earthworks are involved.

This can create delays between planning, engineering and construction.

For commercial projects, this delay can affect more than one consultant. Architects, civil engineers, structural engineers, builders and project managers may all need to respond if ground conditions change the design.

Early soil testing helps reduce this risk.

Soil testing and structural engineering

Soil testing and structural engineering are closely connected.

The soil report provides information about the ground conditions. The structural engineer uses that information to design footings, slabs and related structural elements that suit the site.

If the soil classification or ground condition changes, the structural design may also need to change.

This is why soil testing should be completed before structural design is finalised.

For commercial clients, this matters because late structural changes can affect cost, programme, approval timing and coordination with other disciplines.

Soil testing and civil engineering

Soil information can also support civil engineering decisions.

Civil design often needs to consider earthworks, pavement areas, stormwater drainage, site levels, retaining walls, access roads and construction practicality.

Where ground conditions are poor, variable or filled, the civil design may need to respond.

For commercial and industrial developments, soil testing can help the project team understand site constraints before drainage, pavements, levels and access are finalised.

This is why soil testing should be viewed as part of the wider project planning process, not just a single report.

Common issues found during soil testing

Soil testing can identify several conditions that may affect a project.

These may include reactive clay, uncontrolled fill, soft ground, variable soil layers, poor drainage, moisture-sensitive soils, rock, groundwater influence or evidence of previous site disturbance.

Finding these conditions early allows the project team to respond before construction starts.

For commercial developments, this can help reduce the risk of redesign, unexpected earthworks, footing changes, pavement issues or construction delays.

Soil testing across Geelong and regional Victoria

Ground conditions can vary across Geelong, Ballarat, Warrnambool, the Great South Coast, South West Victoria, Melbourne West and regional Victoria.

A report from one site should not be assumed to apply to another site nearby.

Previous land use, fill, vegetation, slope, drainage, soil type, moisture conditions and surrounding development can all influence the final result.

Each site needs to be assessed based on its own conditions.

Related engineering support

Soil testing often connects with structural engineering, civil engineering and wider project documentation.

For example, soil conditions may affect slab design, footing design, retaining wall design, pavement design, stormwater drainage and site grading.

You can also view PM Design projects to see the range of commercial, industrial, residential, education, healthcare and regional development work supported by the team.

How PM Design supports soil testing and site classification

PM Design provides soil testing and site classification support for builders, developers, commercial clients, homeowners, designers and project teams across Geelong, Ballarat, Warrnambool, the Great South Coast, South West Victoria, Melbourne, regional Victoria and surrounding areas.

PM Design supports AS 2870 site classification, soil reports, footing and slab design coordination, structural engineering, civil engineering and related project documentation.

The team helps projects move from early investigation through to design, documentation and delivery with practical engineering input.

When should you arrange soil testing?

You should arrange soil testing early if you are planning a new dwelling, townhouse development, commercial development, industrial project, building extension, slab design, footing design, retaining wall, car park, access road or project where site conditions may affect construction.

Soil testing should ideally be completed before structural and civil design decisions are finalised.

That gives the project team better information before drawings, pricing and approvals move too far ahead.

Need soil testing or site classification support?

If you need soil testing, an AS 2870 site classification report or engineering support for footing, slab, structural or civil design, PM Design can assist.

Contact PM Design to discuss your site, project type and documentation requirements.

FAQs

What is soil testing used for?

Soil testing is used to assess ground conditions at a site. It can support footing design, slab design, site classification, civil design, retaining walls, pavements and project planning.

What is AS 2870?

AS 2870 is the Australian Standard used for residential slabs and footings. It helps guide footing and slab design based on expected ground movement and site conditions.

Do commercial projects need soil testing?

Many commercial projects benefit from early soil investigation, especially where the project involves new buildings, slabs, pavements, retaining walls, car parks, earthworks, drainage or changes to existing site levels.

Can soil conditions affect project cost?

Yes. Soil conditions can influence footing design, slab design, site preparation, excavation, drainage, retaining walls, pavements and construction methodology.

Should soil testing happen before structural design?

Yes. Soil testing should usually happen before structural design is finalised, because the structural engineer needs reliable site information for footing and slab design.

Does PM Design support commercial clients?

Yes. PM Design supports commercial clients, developers, builders, architects, project managers and property owners with soil testing, site classification, structural engineering, civil engineering and project documentation.