Cass, Heather Willson

Early life and education

Heather Willson Cass graduated from Mt. Holyoke College in 1969 as a Sarah Williston Scholar, Phi Beta Kappa. She went to the Yale School of Architecture, receiving an M.Arch in 1972, and was an Everett Victor Meeks Fellow, an NEA Arts Thesis Fellow, and a Henry Luce Foundation Scholar.

Career in Architecture

Principal, Cass & Associates Architects, PC, 1989- present

Partner, Cass & Pinnell Architects, 1978-88

Principal, Heather Willson Cass, AIA, 1976-78

Luce Scholar, Maki & Associates, Tokyo, Japan, 1974-75

Designer, Keyes, Lethbridge & Condon, Washington, DC, 1972-74

Model builder, Keyes, Lethbridge & Condon, Washington, DC, Summer 1970

General office work, Alfonso Alvarez, Architect, Summer 1968

Major Buildings and Projects

  • Gage House Fort Washington, MD 1993

    The Gage House is located at the intersection of the Potomac River and Swann Creek in suburban Prince George’s Conty, MD. The project is an investigation of two ideas: the use of clear geometry to unify an unruly site, and the reconciliation of a recently developed suburban neighborhood with a historically rural waterfront. The scheme creates layers of privacy which decrease as one moves from the street through the house and sundeck terraces, and finally to an existing dock on the water’s edge. The materials and forms of the main elements of the house (a rectangular masonry bar and a square wood-framed pavilion) are derived from the adjacent context of brick houses, domed barn structures and skeletal wood-framed docks. Living spaces are configured within each element to maximize natural sunlight, privacy, and views.

  • Brown House Addition Washington, DC 1992

    The Brown House commission was a project to add a music room addition to a house designed in 1968 by Richard Neutra. Located on a secluded street fronting Rock Creek Park in Washington, DC, the original house was designed for the Brown family in Neutra’s signature manner as a series of interlocking volumes. The strategy for the addition was to seamlessly continue the elegant language and materials of Neutra’s original design, and to introduce elements from other parts of the house to tie together old and new. An existing landscape wall, extending from the dining room into the front yard, provided a cue for siting the addition The new room is located on the front of the house adjacent to the existing primary living spaces overlooking the park. The interior is finished to match existing materials and provide a neutral backdrop for the clients’ outstanding collection of modern art.

  • Miller-Schiller House Washington, DC 1995

    The Miller-Schiller house was designed to meet the needs of a large and active family who wanted to combine the convenience of an in-town residential neighborhood close to the subway with the tranquility of a woodland setting. The site is located at the edge of the neighborhood, adjacent on one side and in the rear to a large, woooded estate which is now a museum. The house takes the shape of a deformed barbell, with parents and guests’ functions at one end and “noisy” childrens’ functions at the other. A two-story living room with second floor gallery connects the two ends of the house. The deformation results from an accommodation of the house’s location on a corner lot and the desire to focus views away from the street and towards the borrowed landscape of the estate’s woodlands. Clerestory windows on the south (street) side bathe the north facing living spaces in afternoon light.

  • Martin House, Wintergreen, VA 199

    The 3,000 sf vacation house is located in Wintergreen, VA, a planned mountaintop community in the Blue Ridge Mountains. The design of the house serves to tie together the steeply sloping elevations of the lot. Two small gatehouses and a bridge anchor the house to its site, mark its presence on the small cul-de-sac, and permit a grade level entry to the main living spaces on the top floor of the house. A large, propped-cantilever deck off the main level has dramatic views of the valley and distant mountains. Bedrooms are stacked below. The exterior of the house derives its form from the simple additive wood structures of farmsheds and bridges which mark the landscape of the valley below.

  • Lohman House Addition McLean, VA 1984

    Located on a wooded site in suburban Virginia, the Lohman House addition resulted from the client’s desire to open up views from the formal interior living areas of the house to the surrounding wooded site and to create less formal interior and exterior family living spaces as well. The existing structure, a sprawling 1950s developer house, was modified to accept a one-room addition which is the centerpiece of a sequence of interior rooms and exterior garden spaces. Ten-foot high triple hung windows, inspired by those used by Thomas Jefferson, open this family room pavilion to the adjacent terraces, garden and woodland views. A gazebo, on axis with the existing formal living room, creates a visual link to the new family/living room.

Press and Awards

  • Gage House – Residential Design Award, Washingtonian magazine
  • Brown House addition – DC/AIA Merit Award, Residential Design Award, Washingtonian magazine
  • Martin House – DC/AIA Merit Award, Southern Living Home Award
  • Lohman House Addition – DC/AIA Design Award
  • Lohman House published in “House Beautiful, Adding On” Metropolitan Home and Emerging Voices: A New Generation of Architects in America




Institutional Affiliations


Leave a Comment