For the ribbon-cutting at the Washington Heights Library this month, the son of a former custodian returned to his old home. He grew up in what used to be the caretaker’s apartment on the third floor. While his father shoveled coal at night to heat the place, he would go downstairs to read about boat building and navigating by the stars. Ronald Clark went on to become the first in his family to graduate from high school and college, and decades later he built himself a boat and navigated by the stars that he had learned about in the library under him. A few years ago, library officials hired the architect Andrew Berman to revamp the two upper stories of that Andrew Carnegie-era branch on 160th Street. Mr. Berman has now turned the third-floor apartment into a clubhouse for teenagers, and the whole second floor into a double-height palace for young children, with seating nooks and lime-green sofas under towering windows. A snaking, pale-wood bookshelf divides the room into cosseting quadrants, scaling it down for pint-size patrons. Smart, sunny and simple, the redesign feels lofty and homey at the same time, rebooting Carnegie’s original grand-populist vision for the branches. In ways big and small, architects like Mr. Berman have changed New York City this year. Projects like the library branch made it a little more livable and humane. What follows is nothing nearly as disciplined or logical as a list of 2016’s architectural highs and lows in town. It’s more a kind of belated thank you note for a few projects that kept faith with architecture’s ideals and the city’s better self.