Understand the ground before you build

Every successful project starts with understanding the ground beneath it. A well-scoped geotechnical investigation tells you what's below your site, how it will behave, and what that means for your foundations, retaining and earthworks.

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We scope each investigation to the site and the project, not a template. You get what you need to design safely, manage risk and satisfy council, without unnecessary testing or gaps that come back as RFIs.

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Projects we investigate

Auckland Council will often ask for a geotechnical report before it issues consent, especially for subdivisions, sloping or filled sites, and ground that isn't "good ground" under NZS 3604.

• Residential: new homes, extensions, retaining walls, steep sites, pools and driveways

• Land development: feasibility, subdivisions, earthworks, resource consent and 224c

• Commercial and industrial: warehouses, commercial buildings, schools, hardstands and redevelopment

• Infrastructure: roads, stormwater and wastewater assets, culverts, ponds and dams

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What's included

We select methods to suit the project, the site and your budget.

• Hand auger boreholes with shear vane for soil types and strength near the surface

• Scala penetrometer (DCP) for bearing capacity of shallow soils

• Machine boreholes with SPT for deeper soil and rock profiles and groundwater

• Cone penetration tests (CPT) for a continuous soil profile, liquefaction and piles

• Test pits for fill, shallow layers and excavatability

• Groundwater monitoring for levels over time

• Geological mapping for landforms and signs of instability

• Laboratory testing for shrink-swell and soil properties

Machine drilling and CPTs are carried out by specialist contractors under our engineers' supervision.

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What you receive

Practical, project-specific recommendations, not generic commentary. Depending on the project, your report may include:

• Site geology and ground conditions, with logs and a site plan

• Groundwater assessment

• Soil and seismic subsoil classification

• Foundation recommendations

• Earthworks requirements

• Retaining wall and slope stability recommendations

• Liquefaction assessment where needed

• Pavement design inputs

• Construction considerations and geotechnical risks

• Support for building and resource consent

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How it works

1. Send us your plans and the site address.

2. Desk study. We review geology maps, the NZ Geotechnical Database, council records and historic aerials.

3. Proposal. You get a clear scope, fee and programme.

4. Site investigation. Our team carries out the fieldwork with minimal disruption to your site.

5. Report. Clear findings and practical design recommendations.

6. Ongoing support. We answer council RFIs and support you through design and construction.

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Why Gibb Ritchie

• Principal-led. A director is involved in every investigation, from scope to sign-off.

• Chartered professionals. Investigations led by Chartered Professional Engineers (CPEng).

• Local experience. We know Auckland's ground, from North Shore clays and Waitematā rock to volcanic and reclaimed land.

• Practical advice. Solutions that are technically robust, commercially realistic and fit your project.

• Responsive. We know investigations are often on the critical path for design, consent and construction.

• With you to the end. The same team supports you through consent and construction.