To the north and west of "Hospital Alley" along First Avenue, the Kips Bay Plaza complex of two 21-story, slab residential towers is one of the first major projects designed by famous architect I. M. Pei in New York City.

Pei, then an architect with the Webb & Knapp development company headed by William Zeckendorf, collaborated with the architectural firm S. J. Kessler & Sons on the development.

The south tower was completed in 1960 and the north tower in 1966.

Their strict geometry is typical of much of his work: good, solid, clean-cut modernity with no frills. His firm’s greatest fame lies in its later work such as the great East Wing of the National Gallery of Art in Washington, the new glass pyramid entrance to the Louvre Museum in Paris and the Bank of China tower in Hong Kong.

These two long buildings are parallel to, but offset from, one another and are placed horizontally, east-to-west, on the large, landscaped site. An earlier plan for the site, developed by the architectural firm of Skidmore, Owings & Merrill had called for six buildings, but Pei wanted fewer to create more open space.

Kip’s Bay Plaza, as it was originally known, was a significant advance in residential planning in the city, however, as it was the first exposed concrete residential project. Its very high degree of fenestration is notable for providing apartments with very large picture windows. Moreover, Pei recessed the windows sufficiently from the façade to have the recesses qualify as...