This renovation and addition to a century-old stone fisherman’s cabin on the scenic coast of the Adriatic Sea transforms the rustic, single-room structure into a comfortable vacation house. The owners wished to use natural building materials and maintain the authenticity and character of the local stonework. 450 Architects worked in great detail to reconstruct the house using materials found on the small island of Lastovo: stone was quarried from on-site for the walls, cabinetry, countertops, and cistern, local pine was milled for framing and furniture, and roofing tiles were salvaged from local buildings. The primary source of water is rainwater collected by the 7,000-gallon cistern. All interior materials are natural and non-toxic, and the building is constructed to minimize energy use. Through green design and sensitive use of materials, the house remains rooted in its extraordinary natural setting, intimately connected to the sea and mountains.