A Brooklyn Couple Rehabilitate a 19th-Century Duplex

There was no long-term plan—no master vision— in play when Alex Gil and Claudia DeSimio rented a 500-square-foot railroad apartment on the third floor of an old tenement building in Williamsburg, Brooklyn, in 2004. Gil, an architect, and DeSimio, who works in finance, were motivated by pure pragmatism: They needed to flee an apartment in a bland midtown Manhattan high-rise that simply cost too much.