Geotechnical report
Geotechnical reports for a CDC, a DA or a construction certificate
For everything a classification does not cover: council conditions, steep sites, basements, retaining walls, complex ground. A CDC-suitable job is a fixed fee — double the site classification fee. A DA is a custom quote, because a council condition can ask for almost anything.
There are two paths here, and which one you are on decides how the job is priced. A Complying Development Certificate (CDC) job — most single dwellings and additions that meet the applicable code — is assessed against a fixed set of standards rather than by council discretion, so the investigation scope is predictable, and the fee is fixed: double the site classification fee for your zone.
A Development Application (DA) is different. Councils in Sydney regularly attach a geotechnical condition to a development consent, particularly on sloping, filled, waterfront or sandstone-and-clay sites, and the condition can ask for almost anything: more boreholes, deeper ones, specific testing, particular commentary. That variability is exactly why a DA (and a construction certificate condition raised after one) stays a custom quote from your address and the condition's wording.
Either way, we read what has actually been asked for, scope the boreholes to it and to your drawings, and write the report to address it point by point so the certifier can tick it off. Bearing capacity, founding levels, excavation conditions, groundwater and any retaining or drainage recommendations are set out with the borehole logs behind them.
What you get
What the report includes
- Boreholes scoped to the council condition and your drawings
- Borehole logs to AS 1726 and groundwater observations
- Allowable bearing pressure and founding recommendations
- Excavation, retaining, drainage and slope comments where relevant
- Report addressing the consent condition, signed by an engineer
Who it is for
Typical jobs
- Owners and builders on a CDC pathway, most single dwellings and additions
- Owners and builders with a geotechnical condition on a DA
- Architects and designers preparing a DA on a difficult block
- Certifiers who need a condition satisfied properly
Further reading
Before you order
How it works
Three steps from your address to a signed report
Tell us the address
Send the site address and what you are building. Standard sites get the fixed fee straight away; anything else gets a scoped quote before we book.
A field engineer drills the block
We come out with a rig or hand equipment, drill the boreholes, log the soil as it comes out of the ground and take samples for the laboratory where the report needs them.
A signed report lands in your inbox
A geotechnical engineer checks and signs the report. It goes to you as a PDF, ready for your builder, slab designer or certifier.
Questions
Questions about geotechnical reports
- How do I know if my job is CDC or DA?
- Your architect, designer or certifier will know which pathway your approval is going through — it is decided by the planning controls for the site and the scale of what is being built, not by us. If you are not sure, send us the address and what you are building and we will ask the right question, or tell you who to ask.
- What does the council actually want, for a DA?
- Send us the condition wording. Most ask for a geotechnical report by a suitably qualified engineer covering the ground conditions, footing recommendations and the stability of any excavation or slope. We scope the investigation so the report addresses each part of the condition, and we say so in the report.
- Do I need this as well as a site classification?
- A geotechnical report includes the classification where a residential footing is involved, so you do not need both. If you already have a classification and the council now wants more, we can usually build on it.
- Why is a CDC job fixed but a DA is not?
- A CDC job is assessed against a fixed code, so the investigation it needs does not vary much from one compliant job to the next, which is what a fixed fee needs to be honest. A DA is assessed on its merits by the council, and a condition can ask for almost anything — more or deeper boreholes, specific testing, particular commentary — so it is quoted from the address and the condition's wording instead.
Need a geotechnical report?
Send the site address and what you are building. Standard sites get the fixed fee straight away; anything else gets a scoped quote before we book.