Saving an icon and ourselves Cameron Sperance As city leaders and architects across New England consider ways to reinvigorate the three-decker, others are weighing in on why they fell out of favor — and how to improve them even without a costly renovation. From South Boston to Fall River and even on the silver screen in Boston-based films like “Spotlight,” “Good Will Hunting,” and “The Departed,” the three-decker remains an iconic housing stock. Think of it as the original form of affordable housing: Relatives would often live in each of the three residences that comprise the relatively inexpensive-to-develop building, or they might even rent one out for income. “Living in or near a New England triple-decker,” the New York Times wrote, “was like despising the Yankees or skipping work on St. Patrick’s Day.”