 To achieve this, the entire IRT station had to be supported by large crossbeams hanging from the roof of the station box, a construction technique that had never been used previously; the station was also supported by conventional columns from below.The entire feat raised the subway infrastructure under Flatbush Avenue, as well as the avenue itself, by less than an inch while the passageways were widened from .In 2004, the entire station was made a NRHP landmark.