Hart Massey House is situated in the Ottawa residential community of Rockcliffe Park and is one of the few houses built directly on the shoreline of McKay Lake. There are mature trees, shrubs, bushes, flowers, perennial plants, and grassy areas throughout the property, all of which integrate nicely into the sloped site. The house has two storeys: the common areas are on the lower level, while the bedrooms are on the second floor. The exterior façades are smooth and unadorned, and the large glass surfaces expose a structural system based on a steel frame or reinforced concrete. Inside, partition walls on the ground floor are only three-quarters high, contributing to an open plan. The east side of the house, which faces the lake, features floor-to-ceiling windows that provide an unobstructed view of the surrounding landscape. A common colour scheme of beige and black extends throughout the house.
The building has undergone changes over the years, the most important of which was the enlargement of the house to the north in 1993, when a modular box was added on each level. However, the integrity of its aesthetic design, as well as the treatment of materials, have been maintained. Some changes have also been made to the landscaping, in keeping with the architecture of the house. Gardens have been successfully integrated and new varieties of plants and flowers continue to be introduced.
Hart Massey and his family lived in this home until the 1970s. Subsequent owners have carefully restored and renovated the house, while meticulously respecting its original concept.