We are often asked to transform poorly designed houses that occupy spectacular sites. Here the existing home, surrounded by wetlands, is just back of the dune on the Vineyard’s north shore. We reworked the current shell and opened the roof with a balcony and seaward-facing dormers, using broad windows to open the house to the light and the sea. What had been a dingy 1960s-era “colonial” is now an open and bright, expansive contemporary house.