Grosvenor Square is typified by architecture of the early Georgian style with its baroque overtures. It is, however, Neo-Georgian in era having been built in the 20th century. Constructed originally as the Europa Hotel for Grand Metropolitan Hotels and completed in 1964 the hotel was designed by Lewis, Soloman, Kaye & Partners. The interior public areas at that time were designed by Dennis Lennon & Partners who, in the same decade, coordinated much of the work on the great ocean liner Queen Elizabeth II. 

The hotel became a Marriott managed property in 1985 and remains so to this day. Through The Parker Company's London office Larimar was asked to manufacture the oversized arm, lounge and sofa seating in the lower ground floor Club Lounge or Concierge Club in 2007.

Interestingly Grosvenor Square's major resident is the United States Embassy. The building, occupying the entire west side and officially called The American Embassy London Chancery Building, was actually constructed prior to the Marriott Grosvenor Square's Neo Georgian edifice. The modernist style of the Embassy, the largest in Western Europe with 10 floors, 3 of them below ground, was designed by Finnish American architect Eero Saarinen and opened in 1960. In 1989 it was granted Grade II listed status. In 2017 The Embassy will move into a new building designed by Kieran Timberlake at the Nine Elms development on the South Bank. The Saarinen building is rumoured to be a conversion project for a new hotel and will, undoubtedly, pose serious competition for the London Marriott Hotel, Grosvenor Square.