This project is named for the large sail that covers one of the two platforms, known in sailing terms as a ‘gennaker’. The client was searching for a treehouse kit on the internet and found O2 Treehouse. The scope of the project started out as a simple 1, 2, Treehouse cube and grew into a larger scale custom build with two connected platforms, one an open deck with hard ladder entry and the other covered by a watertight canopy and accessed via rope ladder to trap door entry. The final design developed around the client’s magnificent row of three large trees in a row, perfect for hanging structures between and which also shade and camouflage the treehouse activities. A wooden walkway connects the two 10 foot high, cable hung structures, which are surrounded on the ground by three O2 installed swings and zipline. The Gennaker has been inspiring and fun for kids and adults alike, who can all appreciate and enjoy the simple pleasure of life aloft.