Rangitoto Island represents an unusual environment of peculiarly distinct character and the bach builders have been resourceful in adapting to the surroundings. The baches are sited on lava flows at the margins of a blanketing pohutukawa forest and in most cases follow the coastline.
The most obvious architectural variation is expressed through the gable roof and its orientation with the waters edge, which differs from the mainland. The verandahs and porches provide sheltered enjoyment of the forest, rock and sea. They form the transitional space of the colonial building between the inside and outside world. The style also mirrors the bungalow that was taking over from the villa at the time.
The Rangitoto Baches are a rich source of building techniques, and demonstrate methods that range from the totally orthodox through the inventive to the casually improvised. Materials were not always salvaged from conventional building sources. The sea provided some bach owners with an ever-changing selection, with material from ships scrapped and deliberately wrecked on the island another source of useful bits and pieces. This recycling and adaptation of salvage material adds to the architectural individuality of the baches and contributes to their local historical importance.