Public consultation is imminent for a new David Chipperfield-designed luxury hotel and spa on the famous site of the US Embassy in Grosvenor Square, London.

The embassy will soon relocate from the Mayfair location to a new site at Nine Elms, and real estate developer Qatari Diar has commissioned Chipperfield’s studio to breathe new life into the building it leaves behind: a mid-20th century listed structure designed by iconic Finnish American architect Eero Saarinen.

The project will include a 137-guestroom hotel and mixed-use space including five restaurants, six flagship retail units, a spa and a 1,000-capacity ballroom.

An operator for the site has yet to be announced.

“Our design proposals protect and respect the significant architectural and structural characteristics of Eero Saarinen’s design, with a focus on restoring and enhancing this unique building to secure its long-term future at the heart of Mayfair,” said Chipperfield.

“We have studied the building’s design and its history as well as its surroundings to deliver an architecturally and socially coherent proposal, which will transform this purpose-built embassy into a world-class hotel.”

A public exhibition showcasing the design will be held from 11-16 April 2016 at 24 Grosvenor Hill, before the proposal is submitted to Westminster City Council in May.

According to the developers, the project will lead to further public realm works “to improve the setting of Grosvenor Square as an open, expansive green space for residents and visitors to enjoy.”

Lucy Musgrave, founding director of public realm consultancy Publica, said: “This proposal presents a unique opportunity to create a vibrant and dramatically transformed public realm in this part of Mayfair. The project will provide much-improved connections to nearby retail offers and greatly improve the setting of the listed embassy building.”

The US government has maintained a presence in the square since former president John Adams' establishment of the first American mission there in 1785. It has occupied Saarinen’s building – which is the largest US embassy in western Europe – since the 1960s.

The hotel will join many neighbouring high-end hotels, clubs and restaurants in Mayfair, including a £500m Peninsula Hotel, a stylish private establishment at 12 Hay Hill, and Richard Caring’s Sexy Fish restaurant.