[32] Three magnolia trees were planted during a 1939 renovation;[33] by the late 20th century, the Fifth Avenue garden was cited as containing roses, violets, lantana, blue Egyptian lily, and white petunias.

[58] The Piccirilli Brothers designed several pediments for the facade (which were contracted out to other sculptors),[59][60] while Samuel Yellin and John Williams were responsible for grilles and ornamental steelwork.

[62] The tympanum, sculpted by Sherry Edmundson Fry to designs by the Piccirilli Brothers, depicts a female figure modeled on Audrey Munson.

[32] Mark Allen Hewitt et al., the authors of the book Carrere and Hastings, Architects, wrote that the axial plan may have been necessitated by the fact that Frick wanted a large picture gallery extending westward from the north end of the building.

[96] Within the staircase hall is a marble stair[80][100] with a ornate wrought iron balustrade, patterned after a similar railing at St Paul's Cathedral in London.

[162][163] Frick asked two of his art-collector friends, Benjamin Altman and Peter Arrell Browne Widener, to advise on the dimensions of the Eagle Rock gallery.

[165] At the time, Thomas Hastings (who had designed the NYPL Main Branch) had also completed a building for Knoedler & Company, the dealership where Frick bought most of his art, in January 1912.

[173] The Municipal Art Commission approved the Lenox Library's relocation that June,[174] drawing protests from numerous civic and social groups,[175] and Frick withdrew his offer the same month due to the opposition.

[61] The construction contract stipulated that the house had to be completed within 18 months of the groundbreaking,[50] as Frick's lease of the Vanderbilt Mansion was supposed to expire in September 1914.

[187] That month alone, Frick spent $400,000 on European fine art for his residence and hired Jacques Seligmann to transport $2 million of furniture from John Murray Scott's house in Paris.

[91] At the time of the Frick family's relocation into the house, the property was worth $3.1 million including land, making it one of the most valuable structures in the neighborhood.

[202] Despite his previous disputes with Hastings, Frick wrote a letter to the architect, saying: "I think [the house] is a great monument to you, but it is only because I restrained you from excess ornamentation.

[209] Frick acquired pieces such as Hans Holbein's portrait of Thomas Cromwell,[210] and he also owned paintings by such artists as El Greco, Francisco Goya, Frans Hals, Rembrandt, George Romney, Titian, Anthony van Dyck, and Diego Velázquez.

[203] Frick separately acquired more art, such as Gainsborough's painting Mall,[214] four Boucher panels,[215][216] Van Dyck's Countess of Clanbrazil,[217] and a Gilbert Stuart portrait of George Washington.

[225] One visitor, the art dealer René Gimpel, said the house's servants were "dressed from head to foot in black" while the carpet in the gallery wing was "as soft as moss".

[228] Frick abandoned these plans in 1917 due to rising costs caused by World War I-era shortages, and a fence was installed around the empty sites.

[254] Adelaide Frick's death in October 1931 triggered a clause in her husband's will, which gave the trustees permission to open the house and the art collection to the public.

Pope's original plan called for constructing a glass roof above the rear courtyard, removing the porte-cochère, and erecting a new entrance on 70th Street.

The initial proposal did not include modifications to the original library; consequently, any expansion of the mansion at its northeast corner was constrained, and Pope's first plan called for only one additional gallery.

[283][123] The vault doubled as an art storage facility and a bomb shelter,[123][122] as there were concerns that the house could be targeted by air raids during World War II.

[297] The LPC gave the museum permission to demolish the house's original sidewalk in 1983, and the bluestone pavement was replaced with blocks of Canadian granite.

[153] As part of a renovation headed by Frick Collection director Charles Ryskamp in the 1970s, the oval room and east gallery were repainted and cleaned.

[110] When Samuel Sachs II became the Frick Collection's director in 1996, he contemplated expanding the exhibition space, adding a cafe, and relocating the entrance to the house's garden.

[105][107] In 2014, the museum announced plans for a six-story annex on 70th Street designed by Davis Brody Bond,[300][309] which would contain offices and other administrative spaces.

[311] Residents and preservationists opposed the proposed demolition of the 70th Street garden,[43][312] and over two thousand opponents formed a group called United to Save the Frick.

[309] The Historic Districts Council cast an advisory vote against the annex,[313] while artists, gallery operators, and architects wrote an open letter speaking out against the plans.

[329] When the house was being constructed, a Real Estate Record writer said: "In employing Mr. Hastings as his architect, he has made an admirable selection, one which assures the erection of a beautiful and appropriate building.

[333] In a retrospective of Carrère and Hastings's work, Mark Alan Hewitt, Kate Lemos, William Morrison, and Charles D. Warren wrote that "both patron and designer deserve credit for [the house's] ultimate success".

[271] In the 1950s, The Christian Science Monitor called the mansion a "quiet and peaceful retreat",[85] and Town & Country magazine dubbed it one of "the finest examples of [Fifth] Avenue's architecture that fortunately have been preserved".

[336] Christopher Gray of The New York Times said the mansion was "straightforward in most respects, but made peculiar by the long blank limestone finger stretching out on 71st Street".