The Stage 3 expansion of the Tararua wind farm involved construction of 31 new turbines. Cyclical rocking under wind loading requires a strong foundation material and particularly high stiffness. Greywacke rock was the preferred founding material. This paper concentrates on the practical aspects of construction decisions which must be made by the supervising engineer. This aspect does not figure highly relative to other aspects in geotechnical engineering literature, but is an important part of engineering practice.