Originally the museum's trustees had considered adding three subterranean levels beneath the stately garden alongside the Cooper-Hewitt's home in the Carnegie Mansion, a Georgian-style landmark on Fifth Avenue at 91st Street on the Upper East Side.

"If the Cooper-Hewitt were going to cover 9 East 90th in purple glass, we would not review the effect on 9 East 90th, but only consider how it would affect the designated landmark, the Carnegie Mansion," she said.

ANDREW SCOTT DOLKART Manhattan The writer is preparing a history of the Carnegie Mansion for the Cooper-Hewitt Museum.

The Carnegie Mansion and the Cooper-Hewitt Museum: The History of a House (Scala/Cooper-Hewitt National Design Museum, 2002).

This avenue of trees, surrounded by a mansion facade and a garden wall, was transformed for a few brief days into a romantic formal terrace akin to one at the Frick Collection or the Carnegie Mansion.

At the beginning of his junior year at Carnegie Mansion, a prestigious private school, Carlton Dunne IV attempts to go through the year without attracting attention to himself as he has done for the past two years.

The report's tone echoed a prevailing view in the museum world that the Cooper-Hewitt is a sleepy institution hampered by its setting in the ornate turn-of-the-century Carnegie Mansion.

A tour of the Upper East Side area that features the Solomon R. Guggenheim Museum, the Jewish Museum and the former Carnegie Mansion.

Instead of trying to obliterate the ornate wood interiors of the old Carnegie Mansion with big monochrome panels, the show's organizers have decided to let them be.

THIS was well-advised, because the Burdens put their 27- by 46-foot ballroom on the third floor, which must have offered dramatic views to the south over the Carnegie Mansion.