The Northwest Harbor residence is located on a three-acre water front peninsula in the Northwest Woods of East Hampton. Using green technology, saltwater pool, passive and active solar design, and geothermal heating and cooling system, this extensive renovation and addition is being submitted as a LEED Silver candidate. At the time of its original construction, the roof and wall trombe system was meant to control passive heat gain and loss. We faced the design problem of replacing the non-working trombe wall system while keeping much of the original non-conforming 5,000 square foot structure and adding a 7,500 square foot addition, all within a zero carbon footprint. Environmentally sustainable design practices, building methods and material selection are integral to every aspect of the project including the re-vegetation of indigenous plantings.