VEN WITH JUST FLASHLIGHTS in hand, designers Serge Castella and Jason Flinn knew they had found the right new home for themselves. Although the two, partners in life and in business, had lived not far from the tiny Spanish village of Rupià for more than two decades, they hadn’t noticed the small, abandoned house on the edge of town. “Because we spend so much time in the town—having coffee there, buying our daily bread, socializing with the storeowners—Jason and I were told about this little palace-like house
