Avery C. Faulkner, 78, scion of a distinguished family of Washington architects and the designer of numerous structures in the Washington-Baltimore area, including buildings for George Washington and American universities, died Feb. 21 of complications of a stroke at Delray Medical Center in Delray Beach, Fla. He lived in the Washington area for 51 years before moving to Wilmington, N.C., in 2005.

Mr. Faulkner, a modernist architect practicing in a city traditionally wary of modern architecture, tackled what may have been his most intriguing modernist challenge when he moved into the picturesque Virginia countryside near Delaplane. He designed the family home in the shape and spirit of an old country barn. The barns are "the best buildings around," he told The Washington Post in 1993.

Drawn to a barn-raiser's utilitarian disdain for decorative frills, he borrowed the proportions of windows and doors on neighboring barns, along with the steep-pitched roofs of traditional barns, and then made the design his own. Constructed of white-painted brick, his house featured four wings built at right angles from a central core, giving it the appearance from the air of a pinwheel.

Entered by way of a central hall, the house offered vistas in all directions across the rolling Virginia countryside. "It is a plan that dates back to the Romans," Mr. Faulkner told The Post. "More recently, it was adapted by Frank Lloyd Wright."

The Faulkners moved into the house they called Tall Chimneys in 1992.

They had moved out of a more rigorously modern house, a glass-and-brick box Mr. Faulkner designed in the early 1960s on the banks of the Potomac in McLean. The Post noted in 1992 that some critics considered the five-bedroom residence -- "a heretical departure from the McLean-Potomac creed of maximum frontal wealth display" -- to be one of the area's finest modern houses.

Mr. Faulkner was born in Bronxville, N.Y., and grew up at Rosedale, a historic house on 10 acres in Cleveland Park owned by his grandfather, Avery Coonley. The house had been built in 1793 by Uriah Forrest, a friend of George Washington's.

Mr. Faulkner's father, Waldron Faulkner, was one of Washington's best-known architects. His work included the original campus of the Madeira School, offices for the American Association for the Advancement of Science and the Brookings Institution.

His brother, Winthrop W. Faulkner, who died in 2004, was a prominent architect, specializing in contemporary residential architecture.

After graduating as valedictorian of his class at St. Albans School in the District, Mr. Faulkner received a bachelor's degree from Yale College in 1951. He received a bachelor's degree in architecture in 1954 and a master's degree in architecture in 1955, both from Yale. He taught Yale's third-year design course -- a course previously taught by renowned architect Louis Kahn -- and then accepted the Yale Traveling Fellowship.

After serving for three years in the Air Force, he joined the architectural firm of Faulkner, Kingsbury and Stenhouse. He was senior partner of Faulkner, Fryer and Vanderpool Architects from 1968 to 1981, when the firm merged with the Cannon Corp. of Buffalo to become Cannon Faulkner.

Mr. Faulkner's work included seven buildings for George Washington University, 19 buildings for American University and the campus for the Garrison Forest School and the Potomac School. His firm designed a new master plan for the National Zoo in 1971 as well as nine of the zoo's buildings and exhibitions. The firm also did work on the National Portrait Gallery, the National Museum of American Art and 14 buildings for the Smithsonian Institution.

Mr. Faulkner was made a Fellow of the American Institute of Architects in 1980 and was appointed by President Ronald Reagan to the Advisory Council on Historic Preservation in 1987. He was reappointed by President George H.W. Bush. He won numerous regional and national design awards from the American Institute of Architects and a GSA Biennial Design Award for the lion and tiger exhibition at the National Zoo.

His wife, Alice Watson Faulkner, died in 2006. Survivors include three children, Sara Faulkner Maley of Amissville, Va., Waldron Mason Faulkner of Boston and Lydia Faulkner Newman of Wilmington; a sister, Celia Faulkner Crawford of the District; and three grandchildren.