The cause was complications of pancreatic cancer, his daughter, Margo Warnecke Merck, said.  Mr. Warnecke, the son of the prominent Bay Area architect Carl I. Warnecke, established a flourishing architectural practice in San Francisco noted for its commitment to contextualism — a respect for local surroundings when designing a building.  He came to national attention in the late 1950s with his model for a new United States Embassy in Bangkok. His proposal for a light pagoda-like building with slender white stilts that seemed to rise, miragelike, from a lake was never built, but won wide critical attention for its ingenious blending of Western and Eastern forms.  In 1962, Jacqueline Kennedy became dismayed at plans to raze several historic Federal-style houses in Lafayette Square, across from the White House, and erect outsize marble and glass government office buildings in their place. She persuaded her husband to start anew with a more preservation-minded plan.  Mr. Warnecke won the commission, which was not entirely surprising. He had recently taken on a historically sensitive project when he designed a civic center and capitol building for the new state of Hawaii that incorporated the 19th-century Iolani Palace.  Just as important, Kennedy had known him since 1940, when Kennedy spent a few months auditing business courses at Stanford and Mr. Warnecke played left tackle on Stanford’s undefeated “Wow Boys” team that beat Nebraska in the 1941 Rose Bowl.  Later, Mr. Warnecke was drawn into Kennedy’s circle by an old Stanford friend, Paul B. Fay Jr., who had become close to Kennedy when they went through PT boat training together; Kennedy appointed him under secretary of the Navy.  In Lafayette Square, a project that unfolded over the remainder of the decade, Mr. Warnecke preserved the old row houses, and the character of the square, and integrated two large office buildings, the National Courts Building and the New Executive Office Building, by setting them well back from the street in courtyards behind the row houses.  In 1963 Kennedy appointed Mr. Warnecke to serve on the Commission of Fine Arts, which approves all federal building projects in Washington. That fall, the two men went to Boston to review a potential site and plans for a presidential library. Mr. Warnecke also developed a new master plan for the Naval Academy in Annapolis that included a new library and three math and science buildings.  The assassination of the president gave Mr. Warnecke his most visible project, the Kennedy grave site at Arlington, on a grassy slope overlooking the Potomac. Mr. Warnecke proposed a four-part landscape design. In the model, a circular walk led to an elliptical granite overlook, where steps ascended to the marble grave platform.  At the center of the platform, backed by a wall with the presidential seal, a triangular brass font cupped the Eternal Flame, which had been lit by Mrs. Kennedy at her husband’s funeral. In a memo to Mrs. Kennedy explaining his design, Mr. Warnecke wrote that the flame “was stronger than any sculpture or any structure that might be added to it.”  When the model was unveiled at the National Gallery of Art in November 1964, Ada Louise Huxtable, the architecture critic of The New York Times, wrote, “Never have the complexities of a design problem and the difficulties of a site been so painfully and publicly clear, and rarely have results been greeted with such general praise obviously motivated by relief.” She had already deemed Mr. Warnecke “the architect who has done the most to bring a new design frontier to Washington.”  When the grave site was consecrated on March 15, 1967, the wall had been eliminated, and the bronze font had been replaced by a beige circular stone, five feet in diameter, from Massachusetts.  “The total design and composition must be simple,” Mr. Warnecke wrote to Mrs. Kennedy, “and out of its simplicity and dignity will come its beauty.” In an unpublished memoir, Mr. Warnecke wrote that his work with Mrs. Kennedy on the grave site developed into a romantic relationship, according to Kathryn Livingston, who is editing the book. He also discussed the relationship briefly in two books, Edward Klein’s “Just Jackie: Her Private Years” (1998) and Sarah Bradford’s “America’s Queen” (2000). Mr. Klein’s account was widely reported at the time, after People magazine published long excerpts from the book.  John Carl Warnecke was born on Feb. 24, 1919, in Oakland. After earning a bachelor’s degree from Stanford in 1941, he enrolled in Harvard’s architecture school, where he studied with Walter Gropius and completed the three-year course in one year, receiving his master’s degree in 1942. A football injury made him ineligible to serve in the military.  After working for the housing authority in Richmond, Calif., and as a draftsman in his father’s firm, he set up his own architectural practice and developed a reputation for his environmentally sensitive designs for buildings at Stanford and the University of California, Berkeley.  His contextual approach was applied at the Mira Vista Elementary School in El Cerrito, Calif. (1951), which appeared to grow organically out of the hills behind it. His open-space design for the Mabel McDowell Elementary School in Columbus, Ind. (1960) — designated a National Historic Landmark in 2001 — addressed the flat landscape, with its silos, barns and Victorian houses.  “Not many large architectural firms in the United States would spend time worrying about the special qualities of the San Francisco Bay region, the cultural heritage of the Hawaiian Islands or the landscape of southern Indiana,” the architectural critic Peter Blake wrote in 1975 in the Russian-language magazine Amerika. “Warnecke’s firm did.”  By 1977 Mr. Warnecke was running the largest architectural firm in the United States, with offices in San Francisco, Los Angeles, New York, Boston, Washington and Honolulu.  His large-scale projects included the AT&T Long Lines Building on Thomas Street in Manhattan (1974), the Soviet Embassy (1975) and the Hart Senate Office Building (1982) in Washington, and the South Terminal at Logan Airport in Boston (1977).  In addition to his daughter, Margo, of Healdsburg, Mr. Warnecke is survived by a sister, Margaret Putnam, of Windsor, Calif.; his sons Rodger, of Santa Rosa, Calif., and Fred, of San Rafael, Calif.; and four grandchildren.  After 1977 he began scaling down his practice. In retirement, he grew grapes on his ranch in the Alexander Valley and worked on his memoirs, which he completed shortly before his death.  An obituary on Friday about the architect John Carl Warnecke referred incorrectly to the publication Amerika, in which the critic Peter Blake wrote about Mr. Warneckeâs work. It was a Russian-language magazine for readers in the Soviet Union; it was not a âSoviet magazine.â The obituary also misstated the location of the AT&T Long Lines Building in Manhattan, one of Mr. Warneckeâs large-scale projects. It is on Thomas Street, not Thompson Street.  This article has been revised to reflect the following correction:  An obituary on Friday about the architect John Carl Warnecke referred incorrectly to the publication Amerika, in which the critic Peter Blake wrote about Mr. Warneckeâs work. It was a Russian-language magazine published by the United States Information Agency for readers in the Soviet Union; it was not a âSoviet magazine.â The obituary also misidentified the street in Manhattan where one of Mr. Warneckeâs large-scale projects, the AT&T Long Lines Building, is located. It is on Thomas Street, not Thompson Street.  An obituary on Friday about the architect John Carl Warnecke referred incorrectly to the publication Amerika, in which the critic Peter Blake wrote about Mr. Warneckeâs work. It was a Russian-language magazine published by the United States Information Agency for readers in the Soviet Union; it was not a âSoviet magazine.â The obituary also misidentified the street in Manhattan where one of Mr. Warneckeâs large-scale projects, the AT&T Long Lines Building, is located. It is on Thomas Street, not Thompson Street.
Mr. Warnecke was the court architect of the Kennedy administration and the designer of John F. Kennedyâs grave site at Arlington National Cemetery.