An austere, hip-roofed brick house on a high stone foundation, the Paymaster's Quarters has a three-bay facade on the east with a central one-story porch that overlooks the town below. A two-tiered portico with square piers extends across the entire west facade. The trim is simple and unadorned, but the doorways are nicely executed Greek Revival ensembles with side lights and transoms.

Superintendent Symington designed a one-story dwelling to house the paymaster, the second-ranking official of the armory. The central space, a dining room, was lit by a skylight. A decade later, Symington's successor, Henry W. Clowe, added the second story. Because it was one of the newest and best-situated houses in town, officials of both armies used it during occupations of Harpers Ferry. From July to October 1863, General Henry H. Lockwood lived here, and a year later, General Philip H. Sheridan made it his headquarters. During Sheridan's tenure, the west facade was pictured in Frank Leslie's Illustrated Newspaper. After the war, the house became the first home of Storer Normal School. A mansard roof was added in 1883 to provide additional space but was removed in an exterior restoration completed by the National Park Service in 1960. The building now serves as offices.