The house is a two-story, five-bay wide brick building on a rock faced, random ashlar base in the Italianate style.

It has a prominent square cupola and a one-story, wooden porch set on brick piers across the front facade.

The original house was built by industrialist Ethan Flagg (1820-1884), a leading citizen of Yonkers.

In 1996, the property was sold for use as a medical and social service center for people with HIV run by the Greyston Foundation.

[1] Media related to Ethan Flagg House-Blessed Sacrament Monastery at Wikimedia Commons