Cottage then commissioned Charles McKim, principal in the firm of McKim, Mead and White and one of the great architects of the day, to design a new clubhouse. McKim spent the summer of 1903 touring England to examine university towns and country houses, and when he returned in the fall he drew up plans for a three-story brick clubhouse in the Georgian Revival style. McKim was thinking on a grand scale: the dimensions he proposed, 104 feet by 102 feet, with a central court measuring 55 feet by 38 feet, required Cottage to acquire the land behind its original lot before construction could begin.

Modeled on the great Georgian country houses of England, Cottage is a beautifully proportioned structure with two broad bays projecting slightly at either end of the facade. The main exterior features of Cottage as built are a striking, curved pediment with an elliptical window, a strong string course between the first and second floors, white quoins on the corners, a small balcony over the front door, and a widow's walk.