Karekare Beach Residence, Sand Dune Stabilisation

Client:                      Private
Location:                Karekare Beach, Auckland
Project Value:       Undisclosed
Sector:                    Residential, 3 Waters
Completion:          2021


A steep site (30-35°) on sand does not typically constitute a viable building site.  The challenge was to determine a suitable foundation system for the site which included depths of loose sand in the order of 10 m in places. 

GWE carried out a series of hand auger and machine drilled boreholes in conjunction with detailed slope stability analysis to inform foundation and slope stabilization design.  A deep foundation system with tie backs to provide adequate resistance against lateral loads was selected.  The resulting design was confirmed by the structural engineer implementing micropiles, up to 12 m long, that extended

into rock.  The design was externally peer reviewed and approved by Council prior to Building Consent being issued.

In addition to the micropile foundation/tie back system, continuously advanced and cemented retaining walls were constructed along the upslope of the development to protect the neighbouring property.


  • Geotechnical site investigation, on-site wastewater/ stormwater design and management.
  • Geotechnical design analysis to confirm stabilisation options.
  • Earthworks and micropile foundation and tieback installation supervision.
  • Geotechnical design checks during construction monitoring.
  • Coordination with designers site builder and micropile/tieback contractor.