Having admired a project by Shane Blue of Bourne + Blue Architecture in Newcastle, New South Wales, Australia, James and Sue O’Sullivan asked the architect to help them create a beachside family compound in Diamond Beach, about a two-hour drive from their main house. Completed this year, the resulting structure, which comprises four main components wrapped around a central courtyard, easily accommodates the couple and their five children, ranging in age from 23 to 16, as well as extended family and friends. To keep maintenance costs down and to reduce the sizeable home’s carbon footprint, Blue used composite plywood and plantation pine throughout, as well as low-VOC paint, low-e glazing and LED lighting. He installed photovoltaic panels, a hot-water recirculating pump and two large corrugated steel bins that store 5,000 gallons of rainwater just outside the building. When the O’Sullivans aren’t using the house, which was completed in spring, they allow it to be used as a vacation rental.