A dozen diverse buildings --two corporate office structures, three residential complexes, two vacation homes, an elementary school, a visitors center, a library, an art museum and a public marketplace -- have been selected to receive 1985 Honor Awards by the American Institute of Architects.

Hugh Newell Jacobsen of Washington won his fifth AIA Honor Award for a private vacation house on Maryland's Eastern Shore that, according to the report of the nine-member jury, displays "admirable modesty, skillful composition and detailing, and perfect compatibility with climate and site."

Jacobsen has earned such awards for his Bolton Commons town house project in Baltimore (1969), an addition to a house in Chevy Chase (1978) and the interior restorations of the Smithsonian Institution's Renwick Gallery (1974) and its Arts and Industries Building (1980).

Probably the most famous of this year's winners is the Atheneum in New Harmony, Ind., designed by Richard Meier of New York, winner of the Pritzker Prize for Architecture in 1984. This all-white, geometrically complex visitors center, situated in a green field on the outskirts of the historic utopian village, serves as a "breathtaking gateway . . . not only to New Harmony, but to a new way of looking at American architecture," according to the jury.

Other widely published winners include the library at San Juan Capistrano, Calif., by Michael Graves of Princeton, N.J., "a masterful transformation of the Spanish mission vernacular into a modern composition," and the Portland (Maine) Museum of Art by Henry N. Cobb of I.M. Pei & Partners of New York, a building with "elusive and surprising interior" spaces and fac,ades that respect its "historic, smaller-scale neighbors."

G.R. Bartholick, a Seattle architect and planner, was selected for the rehabilitation and restoration of the core buildings in that city's historic Pike Place Market, a job praised as "social design in its best sense, allowing the architect to take a back seat to the people who thrive in its warm and very human embrace." The Middlebury (Conn.) Elementary School by Tai Soo Kim of the Hartford Design Group was selected for providing a "marvelously cheery and refreshing learning environment" despite the "constraints of a tight budget."

The two corporate winners are the Weyerhaeuser Technology Center in Tacoma, Wash., by the San Francisco office of Skidmore, Owings & Merrill, a sleek cedar and glass building that is "an integral part" of its wooded site; and the headquarters of AB Volvo in Gothenburg, Sweden, by Mitchell/Giurgola Architects of New York, a design that "expertly and seamlessly merges art with architecture."

Other residential winners this year included a "fresh interpretation of the New England shingle-style coastal cottage" on Martha's Vineyard, Mass., by Robert A.M. Stern Architects of New York; a midrise condominium project in Cambridge, Mass., by Graham Gund Associates of Cambridge, called "a masterpiece of contextual design"; Roosevelt Solar Village in Princeton, N.J., by Kelbaugh + Lee of Princeton, an "imaginative response to the special needs of the elderly"; and a complex of town houses in Santa Monica, Calif., by Rebecca L. Binder of Santa Monica and James G. Stafford of Los Angeles, that draws upon "high-tech, industrial images" to create a sense of "vitality and adventurousness."