Benjamin D. Phillips (1885–1968), apparently impressed with Janssen and Cocken's design for the company office building ( BU9), commissioned the firm to design his house, one of the finest estates in Pennsylvania. The two-story limestone house is centered on a courtyard, and the heavily slated, steeply gabled roof is dotted with dormers, chimneys, and spires. The architects, with project architect Roy Hoffman and Nicolet and Griswold as landscape architects, succeeded in fitting a grand house and gardens into a relatively small, uneven space without overfilling the property, while at the same time shielding the house from the surrounding city.
Forced to sell by the Great Depression, the house had a series of short-term owners until 1985, when Frederick Koch, heir to a different oil fortune and an art and architecture connoisseur, purchased the house and began to restore and expand it. The New York City firm, with project architects Elaine Felhandler and Sue Steeneken, designed the additions, expanding the house eight thousand square feet down the hill on the southern elevation. The line between the 1920s work and the 1990s work is almost indistinguishable. Young allowed two places where his work would stand out rather than integrate into Janssen's earlier work. The first is a glassed pavilion overlooking the swimming pool and the second is a colonnaded stone gazebo perched at the southwestern corner of the house.