AS 2870 Site Classifications, Soil Testing & Foundation Assessment
Every building starts with the ground beneath it. A professional site classification identifies the soil conditions present on a site and determines how those conditions may influence footing and slab design.
BHM Geotechnical provides site classifications across Adelaide and South Australia in accordance with Australian Standard AS 2870, delivering the soil information required for safe, practical, and suitable foundation systems.
Understanding Soil Conditions for Foundation Design
A site classification, also known as a lot classification, is a geotechnical assessment used to determine the characteristics and reactivity of soil beneath a proposed building site. The classification provides engineers and designers with essential information for selecting appropriate footing systems and slab designs.
Site classifications are carried out in accordance with Australian Standard AS 2870 and involve assessing soil properties, site conditions, and ground behaviour that may influence future building performance.
The information gathered supports:
Every assessment concludes with a detailed site classification report outlining the site conditions and relevant AS 2870 classification.
BHM Geotechnical carries out field investigations, soil testing, and technical assessments to accurately classify sites in accordance with Australian Standards.
Understanding the composition and behaviour of soil is essential for determining how it may respond to environmental changes and structural loading.
Our investigations may include
These investigations provide critical information about the characteristics and performance of the ground beneath the proposed development.
Site classification combines field observations and soil testing to determine the appropriate classification category under Australian Standard AS 2870.
Our assessments may include
The resulting site classification report provides designers with the information required to develop suitable footing and slab systems.
AS 2870 site classifications are based on soil reactivity, expected ground movement, and site-specific conditions. Classifications may include Class A, S, M, H1, H2, E and P depending on the characteristics of the site.
Our assessments may identify
Class P may apply where conditions such as uncontrolled fill, abnormal moisture, soft soils, slope instability, trees, or other site constraints influence foundation performance.
We deliver AS 2870 site classifications, soil testing, and detailed reports for residential, commercial, and development projects across Adelaide and South Australia.
BHM Geotechnical combines practical field experience, advanced testing methods, and detailed knowledge of Australian Standards to provide reliable site classification assessments. Our geotechnical engineers understand the relationship between soil conditions, ground movement, and foundation performance, helping builders, homeowners, and designers achieve suitable construction outcomes.
Site classifications completed in accordance with recognised Australian Standards.
Field investigations and laboratory testing provide reliable information about soil characteristics and behaviour.
Reports deliver relevant soil data to assist footing and slab design.
Assess soil conditions, ground behaviour, and site-specific factors influencing construction.
Efficient investigations, clear reporting, and timely communication to support project schedules.
Different developments require an understanding of soil conditions to ensure appropriate foundation solutions are selected.
Determine soil classifications and foundation requirements before construction begins.
Assess existing sites to support new footing and slab design.
Understand how existing and proposed structures interact with site conditions.
Provide soil information for planning and future building requirements.
Assess ground conditions for small multi-unit and Class 1 residential developments.
Site classifications are influenced by more than soil type alone. Across Adelaide, factors such as reactive clay soils, moisture variation, site history, and previous development can significantly affect ground behaviour and classification outcomes.
Factors commonly considered include
A Structured Approach to Understanding Soil Conditions
Review the proposed development, available site information, and assessment requirements.
Undertake site inspections and collect soil samples to understand ground conditions.
Test samples to determine soil properties, classification characteristics, and reactivity.
Assess testing results and determine the appropriate site classification in accordance with Australian Standards.
Provide a detailed report outlining soil conditions, AS 2870 classification outcomes, soil reactivity, and geotechnical information.
A professional site classification provides the information required to select suitable footing systems and minimise issues related to soil movement.
Identify how soil may expand or contract due to changes in moisture conditions.
Provide the soil information required for footing and slab design by structural engineers.
Ensure soil classifications align with recognised Australian Standards.
Understand ground conditions that may influence long-term building performance.
Provide reliable soil information before foundation works commence.
Identify challenging soil conditions early in the development process.
Our AS 2870 site classifications provide the soil information required for footing and slab design, builder-ready reporting, and informed construction planning.
Request a Site ClassificationA site classification report provides information about soil conditions, soil reactivity, and the appropriate classification of a site in accordance with AS 2870. The report assists engineers and designers in selecting suitable footing and slab systems for construction.
An AS 2870 site classification identifies the reactivity and characteristics of the soil beneath a building site. The classification helps determine foundation and slab requirements for residential structures in accordance with Australian Standards.
No. A site classification identifies soil conditions and ground reactivity. The information is then used by the structural engineer, footing designer, or builder's design team to develop an appropriate footing or slab design.
AS 2870 classifications include Class A, S, M, H1, H2, E, and P. These categories describe expected soil reactivity and ground movement. The classes are defined by the following characteristics: A (stable, sand/rock), S (slightly reactive), M (moderately reactive), H1/H2 (highly/very highly reactive), E (extremely reactive), and P (problem site, e.g., fill or soft soils). As classifications progress from A through E, the potential for soil movement generally increases. Class P applies when additional site-specific conditions require engineering assessment. Adelaide's Keswick and Hindmarsh Clays are among the most reactive in Australia and commonly produce M, H1, H2, or E classifications.
The process involves a site inspection, soil sampling, laboratory testing, and geotechnical assessment. The collected information is analysed to determine the appropriate site classification and provide a detailed engineering report.
Class M sites contain moderately reactive soils, while H1 and H2 sites contain highly reactive soils with greater potential for ground movement. Class E sites contain extremely reactive soils. Class P sites are problem sites where factors such as uncontrolled fill, trees, slope instability, abnormal moisture conditions, or other constraints require specific engineering consideration.
