Schnapper Rock Subdivision
Earthworks observation, testing and certification for a six-lot hillside subdivision with timber pole retaining walls.
- Location
- Schnapper Rock, North Shore
- Sector
- Residential subdivision
- Year
- 2026
Project overview
Gibb Ritchie provided geotechnical observation, testing and certification during the earthworks for a six-lot residential subdivision in Schnapper Rock, on Auckland's North Shore. The sloping site was formed into building platforms and a shared accessway using engineered fill, held by timber pole retaining walls.
We were engaged as the geotechnical certifier for the earthworks, following the work through construction and preparing the completion reporting Auckland Council needs to sign off the new lots.
Key challenges
- A sloping site formed into building platforms with fill and retaining walls
- Old building rubble and unsuitable material found during stripping
- Wet winter weather making the fill hard to compact
- Expansive clay soils that affect future foundation design
Our solution
We visited site at key stages to check the ground before fill was placed, confirm conditions in the retaining wall pile holes, and observe fill placement and drainage. The fill was tested throughout the works to confirm it met the project specification.
We also tested the accessway subgrade and classified the site soils, so the people designing the future houses have the information they need.
The earthworks were completed and certified for six new residential lots and a shared accessway. Our completion report gives each lot clear foundation guidance and building restrictions, so future owners and designers know what they are building on.
