The Landmarks Preservation Commission describes the building as, "... a unique example of an apartment house of the type utilizing terracotta. This is the finest building of its type in New York City. .... at Alwyn Court, instead of limiting the decoration, the architects went to the other extreme, leaving hardly any surface undecorated. Such detail would have been out of the question in stone, but by taking advantage of a material in vogue at that time, 1907-08, the architects were able to produce the entire commission for less than a million dollars. This material was terra-cotta, a cast clay product glazed and fired. Since each mold could be used repeatedly the amount of decoration desired was only limited to the number of motifs the budget allowed."  In 2020 a 2 bed apartment in Alwyn Court was listed for sale at $2,175,000.

The building's Wikipedia page says that it is, "... a 12-story apartment building ....  designed by Harde & Short in French Renaissance style  ....  The building was constructed at a time when wealthy New Yorkers, some living in the city part-time, began to shift from mansions to apartment living. Seventh Avenue was a hub of new luxury buildings. The Alwyn targeted this market, with perhaps the most lavish structure yet. Glazed terra cotta was a new material, and the facade dripped with ornate detail in that medium. Typical apartments had 14 rooms with 5 bathrooms, renting up to $10,000 per year; there was even one 24-room duplex, at $22,000. Many of the apartments had enormous rooms of about 18 by 30 feet.  The twelfth floor contained 34 rooms for servants quarters."