Barnet's design was also rare in being one of the earliest mass concrete lighthouses in Australia and, standing at 29 metres, was the tallest tower in NSW at the time. Concrete construction was a bold initiative for the period and, although some small houses were built of the material prior to 1880, no public buildings (and certainly none as substantial as the Green Cape Lightstation) had been constructed using concrete. The use of Bittangabee Bay as a trans-shipment point for building materials indicate the extremely difficult logistics involved in the construction of a mass concrete structure in an isolated location during this period.