Henry A. Frost Jr. was an architectural designer who collaborated on many buildings along the Route 128 corridor, but his master work was his own home, a one-story ranch-style house on a bluff overlooking a marsh in Scituate.
Mr. Frost was an advocate of clear, simple design. In the 50 years since his redwood house with floor-to-ceiling windows was built, he added patios, decks, and other refinements to blur the distinction between indoors and outdoors.
''He might add a window to a wall or extend the deck. He could be fussy, particularly when it came to the house," his wife Barbara A. (Pendill) said yesterday of her husband, who died Sept. 9 in South Shore Hospital in Weymouth. He was 84.
''He was always tweaking something," his son, Andrew Frost of New York City, said yesterday.
A quiet man with a wry wit, Mr. Frost was the son of Harvard architecture professor Henry Atherton Frost.
He grew up in Cambridge, where architects I.M. Pei and Philip Johnson were among the frequent guests for dinner.
He graduated from Brown University, serving in the US Coast Guard Reserve while an undergraduate, and from Harvard's Graduate School of Design.
Mr. Frost worked briefly for a few Boston architecture firms before joining Cabot, Cabot, and Forbes, where, as vice president, he oversaw the design of buildings along Route 128. Among his clients were Polaroid, Arthur D. Little, and Canada Dry.
In the early 1960s, Mr. Frost left Cabot to open his own architectural firm, Henry A. Frost and Associates. Among his firm's projects was Farrar Pond Village Condominiums in Lincoln.
Mr. Frost and his family moved to Scituate in the 1950s. When he and his wife were installing wallboard in the house he designed, she went into labor with Andrew, their second son.
He restored a 1949 Jaguar Mark V that he enjoyed driving around town and drew admiring glances on his weekly trips to Bergson's in Cohasset for ice cream.
He also enjoyed boating and owned three successive boats named Frosting, which he docked at the Scituate Harbor Yacht Club, where he and his wife had dinner every Friday night in the summer, at Table Four, overlooking the harbor.
He was particularly fond of models of cars, planes, and trains, which he made and displayed in his studio at home.
''He also painted; he had an artistic bent," said his wife.
''He was understated, not one to draw attention to himself, but he knew how to have fun," his son Andrew said.
''He was friendly, but kept to himself," Jack Chesley, his neighbor in Scituate and classmate at Harvard, said yesterday. ''Now, don't tell all you know," was his favorite expression, Chesley said.
Besides his wife and son Andrew, Mr. Frost leaves another son, Peter of Bangkok, and five grandchildren.
A memorial service will be held at 11 a.m. tomorrow in St. Stephen Episcopal Church in Cohasset. Burial is private.