Frequently Asked Questions

Yes. Under the National Construction Code and Australian Standard AS 2870, a site classification report is required before a building designer or engineer can specify the correct foundation system for any new dwelling or extension. Your private certifier or council building approval will require a current site classification report as part of the documentation package. Without it, a building approval cannot be issued.

AS 2870 is the Australian Standard for residential slabs and footings. A site classification report under this standard assesses the soil reactivity at your site — how much the soil is likely to move in response to moisture changes — and assigns a classification that determines the appropriate footing design. The classifications range from Class A (stable, non-reactive) through to Class E (extremely reactive) and Class P (problem sites requiring site-specific engineering input). The report is prepared by a qualified geotechnical consultant and must be accepted by your certifier and building designer before construction begins.

Our trained field technician visits your site and conducts a series of hand auger borings or machine-drilled holes at strategic locations across the lot. Soil samples are collected at depth intervals and assessed for soil type, consistency, and reactivity. The entire site visit typically takes between 30 minutes and two hours depending on the size of the lot and the complexity of the soil profile. You do not need to be present on the day, but we do need clear access to the site. We will confirm access requirements when you book.

Reports are typically delivered within five business days of the site visit. In many cases turnaround is faster. Your certified report is delivered digitally as a PDF, ready to submit to your certifier or building designer. If you have an urgent requirement, contact us when booking and we will do our best to accommodate your timeline.

There is no formal expiry period prescribed in AS 2870 or Queensland building legislation. However, certifiers and councils may query a report they consider too old, particularly if significant time has passed since the investigation. More importantly, the conditions at a site can change over time — excavation, filling, the addition of large trees, changes to drainage, or nearby construction can all affect the soil profile and potentially alter the classification. If your site has changed since the original investigation, or if a certifier has raised concerns about the age of an existing report, we recommend commissioning a new investigation.

Yes, in most cases. A single AS 2870 site classification report is generally accepted by both the development approval and building approval stages. Some councils or certifiers may have specific requirements, so it is worth confirming with your certifier early in the process. If you are unsure what is required for your project, contact us and we can help clarify.

The classification reflects the reactivity of the soil — how much it is likely to move with changes in moisture content. Class A sites are stable and non-reactive, typically sand or rock. Class S sites have slightly reactive clay. Class M sites have moderately reactive clay, which is very common across South East Queensland. Class H1 and H2 sites have highly reactive clay and require more robust footing designs. Class E sites are extremely reactive. Class P sites are problem sites — not necessarily the worst, but ones where standard footing designs cannot be applied without additional site-specific engineering input. Class P can result from filled ground, soft soils, poor drainage, or other conditions that require individual assessment by a structural engineer.

For a standard investigation we need vehicle access to the site, or at minimum clear pedestrian access across the lot. If vehicle access is not available and the investigation must be completed by hand, additional charges may apply. Gates should be unlocked or a key/code provided. If the site has restricted access or unusual conditions, let us know when booking and we will advise accordingly.

Yes. We regularly combine a site classification with a wastewater design assessment or groundwater standpipe installation in a single site visit. Combining services reduces mobilisation costs and is often more convenient for builders and developers managing multiple trades. Contact us to discuss what you need and we will confirm what can be completed together.

We service South East Queensland, including Brisbane, the Gold Coast, the Sunshine Coast, Moreton Bay, the Scenic Rim, Ipswich, and surrounding areas. If you are unsure whether your site falls within our service area, contact us and we will confirm.

Yes, absolutely. We are happy to talk through your project and advise which services are required. Most clients only need a standard site classification, but some projects — particularly those on acreage, with on-site sewage, or with unusual site conditions — may require additional investigations. Call us any time during business hours and we will give you a straight answer.

Yes. All site classification reports are prepared in accordance with AS 2870 — Residential Slabs and Footings. Reports are signed and certified by a QBCC licenced site classifier and are accepted by private certifiers and councils across South East Queensland.

Yes. Express Soil Testing holds a Queensland Building and Construction Commission (QBCC) site classifier licence (Licence No. 1307190). This is a mandatory requirement for anyone preparing AS 2870 site classification reports in Queensland. You can verify our licence on the QBCC licence search at qbcc.qld.gov.au.

Reports are delivered as signed PDF documents by email. They include the site classification, supporting soil profile logs, test data, and all information required by your certifier or building designer. If you require additional copies or a specific format for your records, let us know.