Through a source error, one of the architects winning an American Institute of Architects honor award for the restoration of New Melleray Abbey in Dubuque, Iowa, was omitted. Willoughby Marshall, Cambridge, Mass., should have been credited with the spatial concept and preparatory work.

Georgetown Canal Square, an old warehouse complex stripped down and jazzed up for the '70s, has won one of this year's American Institute of Architects Honor Awards for updating old buildings for architect Arthur Cotton Moore. The awards will be made in June.

Canal Square, once a goup of five crumbling, old building, is now what Moore calls "a town square" - two stories of shops and restaurants, topped with offices, all centered around a great courtyard. The result has much of the feeling of the European castle town.

Since the building was finished in February of 1971 at a cost of $2.5 million, the occupancy has stayed at 100 per cent. A variety of concerts and other entertainments take place in the courtyard.

The primary success of the building has come in the way it links the romatic old brick-and-arch construction with the clean lines of today's design. Moore, for instance, cleaned off the old plaster on may interiors, leaving the brick exposed with all its holes and niches, the marks of age. One of other hand, the new construction is all adamantly modern. Thus the eye knows instantly what's new and what's old, and feels the honesty of the result.

The building has ramps and elevators to serve the handicapped.

Canal Square was Moore's first large-scale commission. Since then, he has applied a similar style of updating old structures while preserving their ambience to the Cairo apartments and the Foundry in Washington, and the Bedford-Stuyvesant Community Center in New York. He is one of the architects in the finals on the restoration of the Old Post Office in the Federal Traingle here.

I.M Pei and Partners, architects of the new National Gallery of Art building, received two honor awards for new buildings. Pei holds 16 AIA honors, more than any other architect to be so recognized in the honors program's 29 years.

One of Pei's awards this year will come as a surprise to many non-architects. The award is for the John Hancock Tower on Hancock Place in Boston, the tall tower whose windows mysteriously blew out over and over again leaving it for a time boarded up with plywood. The jury seemed to tip in favor of its form over function, commenting:

"However, carefully considered in its context, it is an elegant, subtle shaft that mirrors such surrounding structures as Trinity Church and the copley Plaza Hotel . . . As an object on the skyline, it catches the sun, reflects the sky, and acts as an effective new landmark for downtown Boston. It is perhaps the most handsome reflective-glass building. History may show it to be the last great example of the species."

Pei also won an honor award for Spelman Halls at Princeton University.

Winners of honor awards for updating old buildings in additional to Moore, were Navy Pier Restpration, Chicago, by Jerome R. Butler Jr., city architect; New Melleray Abbey, Dubuque, Iowa, By Theodore Butler of Hammel, Green and Abrahamson, Inc., with general and liturgical design and detail by Frank Kacmarck; Mercantile Wharf Building, Boston, by John Sharratt Associations, Inc.; College Center, Vassar College, Poughkeepsie, N.Y., by Shepley Bulfinch Richardson and Abbott; and Franklin Court, Philadelphia, by Venturi and Ranch.

Eleven awards went to new buildings including the two to Pei. Others were; the Penn Mutual Tower, Philadelphia, by Mitchell/Giurgola; Pennzoil Place in Houston, Tex., by Johnson/Burgee of New York with S. I. Morris Associates of Houston; Bronx Development Center in Bronx, N.Y., by Richard Meier and Associates; the Concord Pavillion, Concord, Calif, by Frank O. Gehry and Associates; Humanities and Social Sciences Building for Southern Illinois University, Carbondale, by Geddes Brecher Qualls Cunningham; 1199 Plaza of New York City, by Hodne/Stageberg Partners of Minneapolis; William J. Campbell Courthouse Annex of Chicago, by Harry Weese and Associates; Vacation house in Mt. Desert, Maine, by Edward Larrabee Barnes, New YOrk; and Elderly Residential project, Cidra Municipality, Puerto Rico, by Jorge Del Rio and edwardo Lopez of Rio Piedras, P.R.

The energy implications of the buildings were also considered in the judging. And four were cited for barrier-free design for the handicapped: the Navy Piev Restoration, the Southern Illinois University building, the Bronx Center and the Mercantile Wharf.