Designed in the International Modern style, Busáras is also a stop on the Red Line of the Luas system, in Store Street just before the terminus at Dublin Connolly railway station.

Áras Mhic Dhiarmada ("Mac Diarmada House") is the official name of the building, which also includes the headquarters of the Department of Social Protection.

The prospect of a tall modern building imposed behind the Custom House generated considerable criticism from the public, and led to assurances from the Corporation that advice would be sought on the approval of any plans.

In this plan, an 8-story block was mounted on a 2-storey bus station podium at the rear of the site, but it was deemed too tall as regards fire safety, and that the tower would impact on the right to light of other buildings on Store Street.

[2] Due to financial losses in 1947, CIÉ was unable to continue construction and a new Irish government, led by John A. Costello, halted the project.

Owing to financial strain, CIÉ sold the building to the Irish state and set about planning a more basic and utilitarian bus station in Smithfield.

[2] Construction on the site remained stopped from 1948 to 1951, leaving a "vast concrete carcass"[3] unfinished with Myles na Gopaleen naming it the "bust station".

It was the election of a new Fianna Fáil government in 1951 which had campaigned for the retention of the bus station, that ensured the project was completed for its intended purpose.

[2][4] The building has an L-shaped plan with two rectilinear blocks of differing heights sitting at right angles, with a circular hall at the ground floor designed in an International Modern style, influenced strongly by Le Corbusier.

The building incorporated a number of materials to create texture, such as brass, Danish bronze, copper, Portland stone cladding, Irish oak flooring, terrazzo stairways, and mosaics designed by Patrick Scott.