Geotechnical engineering investigations

Geotechnical Investigations

Councils frequently mandate that applications for resource or building consent incorporate a Geotechnical Assessment Report, often known as Geotech or Soil Report, to support the consent application. A Geotechnical Report offers a comprehensive analysis of the soil types and strengths present on the site, utilising tests such as the Shear Vane Test or Scala penetrometer testing. This report includes essential values and recommendations necessary for the structural engineer, architect, and other professionals involved in designing and constructing the house or building.

These reports provide insights into the soil composition and other pertinent information, forming the basis for subsequent site inspections in later stages of the process. Geotechnical reports also incorporate potential architectural blueprints, which are scrutinised and integrated with the geotechnical scoping. This facilitates a comprehensive assessment of construction-related risks, followed by recommendations for effective site stability mitigation strategies, as discussed within the reports.

Additionally, soil compaction, ground testing and other laboratory tests may be necessitated to acquire further insights into the soil characteristics.

Site Stability Assessments

If the site features a sloping ground (as a rule of thumb, a gradient of greater than 14 degrees is considered a criterion for a sloping ground), then it is necessary to conduct a slope analysis and issue a report as part of the building consent application process prior to the commencement of any earthworks or construction activities. It is important for the engineers to thoroughly analyze the conditions of the slopes as they are known to be associated with hazards which are to do with the long term safety of the properties concerned.

Groundwater monitoring

Shire offers comprehensive groundwater monitoring services. Groundwater assessment reports serve various purposes, including confirming the groundwater regime to gain insights into soil stability. We determine groundwater characteristics and anticipate how they may evolve over time. Additionally, these reports are frequently essential for activities falling under consent E7, such as groundwater extraction, impoundment, or diversion.

Retaining Walls

Constructing retaining walls for subdivisions, extensions, excavations, site stability, landscaping, or other purposes demands meticulous design and supervision by engineering specialists. Shire Engineering Consultants undertake comprehensive site investigations to assess soil conditions and site stability, incorporating stormwater and groundwater modelling where necessary. This information is used to design effective retaining wall solutions aimed at mitigating project risks. Shire Geotechnics offers expertise in designing various types of retaining walls, including timber pole retaining walls, gabion baskets, and crib walls.

Site Inspections

During the construction phase, councils typically mandate that a suitably qualified engineering professional inspect various stages of the build to ensure compliance with building and consent conditions. Shire Geotechnics is authorised by numerous councils across New Zealand to fulfil this sign-off requirement.

Generally, Shire Geotechnics has already been involved in site investigations and the preparation of geotechnical reports, offering foundation and/or retaining wall design recommendations to clients and their team of structural engineers, architects, and planners (if engaged). Throughout the construction phase, the findings and recommendations outlined in the geotechnical report serve as the basis for approvals.

In cases where another company has authored the report or their recommendations have resulted in on-site issues, Shire Geotechnics can be engaged to provide sign-off and recommendations to attain consent. Upon the satisfactory completion of all works, we will issue a Producer Statement (PS4) to the council on your behalf.

Additional site-based inspection services offered include:

  • Pre-purchase appraisals
  • Building settlement assessment
  • Land stability analysis
  • Earthworks evaluation
  • Retaining wall dilapidation surveys


With over 20 years of experience conducting site inspections in Auckland and across New Zealand, you can rely on Shire to ensure the success of your development project.

Does your project require a geotechnical report? Our Geotechnical design engineers are here to help.

Get in touch with us to discuss your requirements.