The Cunard Building was designed in the Italian Renaissance style by Benjamin Wistar Morris, in conjunction with consultants Carrère & Hastings.

The structure was designed around an irregular street grid and is located directly above a subway line that crosses the building site diagonally.

The first floor interior contains an elaborately decorated lobby, as well as a similarly opulent Great Hall, which extends 185 feet (56 m) with a 65-foot-tall (20 m) dome.

[8][9] The Cunard Building was one of several structures built on the lower section of Broadway in the early 20th century that would be affiliated with the maritime trade.

[19] The New York City Subway's BMT Broadway Line (carrying the R and ​W trains) crosses diagonally underneath the Cunard Building from northwest to southeast.

[24][25][26] During construction, the engineers considered and rejected an idea for placing the Cunard Building's girders on the roof of the Broadway Line tunnel, since that would have resulted in vibrations every time a subway train passed by.

The foundation columns were placed as close to the subway tunnel as possible, in order to reduce the length of the trusses, which would have had to carry heavy loads.

The rock surface underneath the building site was closer to the ground on the western side of the lot, requiring extensive excavation.

The wall served several purposes: it closed the cofferdam, underpinned the subway, and provided support for the columns on the southern side of the Cunard Building.

[39] The building's original owners had decided against putting "miscellaneous minor business adventures" in the lobby, such as newsstands, shoe-shine stands, and cigar shops.

[37][40] The lobby ceiling was painted by Ezra Winter and sculpted by Carl Jennewein, and contains decorations of marine animals and children.

[32] Wrought-iron screens topped by lunette grilles, designed by Samuel Yellin, separate the passageway from both the lobby to the east and the Great Hall to the west.

[41][43] It contains several Beaux-Arts design elements, including a symmetrical plan, transverse axes, a central dome, and various walled-off areas.

[50] Barry Faulkner painted murals of maps into the walls of the Great Hall's niches, depicting the routes operated by the Cunard Line.

[9][35][51] The pendentives of the Great Hall's dome include depictions of oceanic explorers Leif Erikson, Christopher Columbus, Sebastian Cabot, and Francis Drake.

[9][51][52] On the Great Hall's floor is a marble compass surrounded by a bronze frieze, designed by John Gregory as an "allegory of the sea".

The school space contains a cafeteria; 30 classrooms; a library; a 400-seat auditorium; and a 40,000-square-foot (3,700 m2) athletic complex with a gym, swimming pool, and rock climbing wall.

[5] According to a 1910 photograph, the buildings on 13-27 Broadway were largely commercial and included a restaurant, art publishers, the Anchor Line steamship company, hatters, and the Stevens House.

[37][59][60] Meanwhile, the lots facing Greenwich and Morris Streets contained Manhattan Railway Company's lost-property building and the late vice president Aaron Burr's former house.

Irons & Todd eventually hoped to turn over the land to the Twenty-Five Broadway Corporation, a subsidiary headed by an official for the Cunard Line.

of the modern city[61] Due to World War I, further planning was delayed until June 1919 when Morris was authorized to create "working drawings, specifications and contracts".

[20] The demolition of the Stevens House began in July 1919, at which point the Cunard Building's final plans were publicized, showing that it was to comprise only 21 stories.

[19] Construction was hindered by the presence of subway lines directly underneath the building site, as well as the irregular plot shape and "unknowable" costs.

[20] During construction, the underground BMT Broadway Line was carried on a concrete bed held by quicksand above the bottom of the Cunard Building's excavation site, in order to dampen the noise.

The presence of the subways, combined with the fact that the Cunard site had been assembled from numerous separate plots, made construction more difficult.

[66] At the building's opening, Cunard and Anchor Lines occupied the Great Hall, lowest three stories, basement, and top floors.

[65] This was attributed to relatively low rents, the inclusion of 21-year leases, the timely completion of the project, and a shortage of available office space in the Financial District.

[75] In 1955, the owners completed a $3 million project to add air conditioning to the Cunard Building, one of the largest such retrofits in an existing structure in the city.

[81] The United States Postal Service leased the Great Hall in 1974, intending to relocate its post office from the nearby Alexander Hamilton U.S.

In 2002, Deloitte leased three floors of the Cunard Building after its previous offices at the World Trade Center were destroyed in the September 11 attacks.