A Historic Transformation: From US Embassy to a Hospitality Masterpiece.. Rosewood Opens in London

After a full decade since David Chipperfield Architects won the development rights amid fierce competition with engineering giants like KPF and Foster + Partners, the final chapter in the story of the transformation of the old US Embassy in London has concluded. The luxurious Chancery Rosewood hotel has officially opened its doors to guests, offering an exceptional accommodation experience within 144 rooms and suites housed in a building steeped in history.

From Diplomacy to Hospitality: The Building’s Journey Through Time

This opening marks the endpoint of a complex real estate transformation journey. It all began in 2008 when the United States formally announced its intention to leave its long-standing diplomatic headquarters in Grosvenor Square in the upscale Mayfair district. This building, designed by the American-Finnish architect Eero Saarinen and opened in 1960 (as his only project in the UK), was destined for a new chapter.

The motivation behind this move was partly the growing security concerns that made it difficult to secure the old building in central London. Indeed, the embassy moved to its new $1 billion headquarters in the Nine Elms area on the South Bank of the Thames, a building designed by the American firm KieranTimberlake and opened in 2017. As for the Saarinen building, it was sold in 2009 to the Qatari real estate development company “Diar” for an undisclosed sum, in the same year the building was listed as a “Grade II” structure on England’s Heritage List, imposing strict restrictions on any future modifications.

Chipperfield’s Vision: Between Heritage Preservation and the Necessity of Modernization

David Chipperfield Architects led the delicate transformation process of the prominent building, which faced significant complexities and challenges in its early stages. The primary goal was to preserve the massive U-shaped structure on the famous square by meticulously restoring its historic stone facades.

At street level, the building was reintegrated with its urban surroundings after being liberated from the dense security obstacles like bollards and barriers added over the years. The design reconnected the building to the public space, integrating the hotel’s ground-floor amenities—including retail spaces and restaurants—with a modern landscape that interacts with the daily life of the square. As the firm stated: “Reasserting the building’s presence as part of Grosvenor Square forms the fundamental design premise. This concept is based on preserving and enhancing the modern architectural qualities while responding to the client’s ambitions to ensure the building’s long-term functional and economic viability.”

Reviving Saarinen’s Vision Inside: From a Concrete Ceiling to an Added Floor

Inside the building, the design process, overseen by interior designer Joseph Dirand, sought to “enhance Saarinen’s original vision.” One of the most prominent features revived was the building’s distinctive wavy concrete ceiling. It was restored and expanded after removing the internal office partitions built during the building’s use as an embassy, which had obscured this unique architectural element and limited the flow of space.

As for the upper floors, they were largely rebuilt behind the preserved original stone facade. A completely new sixth floor was added, and above it, a penthouse “pavilion” containing luxury suites and premium public facilities was constructed atop the existing structure. Meanwhile, the basement levels were radically developed to accommodate a large ballroom, a world-class spa, car parking, and other service facilities. To ensure restoration accuracy, over 4,000 individual elements of the building were carefully disassembled, cleaned, and refurbished before being reinstated in their original locations.

Saarinen’s Legacy: A Recurring Pattern of Adaptive Reuse

It is worth noting that the former US Embassy in London is not the first Eero Saarinen-designed building to undergo a radical adaptive reuse conversion into a hotel. In 2019, the famous TWA Flight Center at New York’s JFK Airport—another Saarinen masterpiece—was saved from neglect and transformed into a luxury hotel after an intensive restoration led by Beyer Blinder Belle. In a more recent example, Saarinen’s former embassy in Oslo was redeveloped into a mixed-use office complex, confirming the enduring value and adaptability of this architectural genius’s heritage.

✦ ArchUp Editorial Vision

The article discusses the architectural transformation of the former US Embassy in London into a luxury hotel, highlighting the adaptive reuse process led by David Chipperfield. From an analytical perspective, the challenge of balancing the preservation of the historical identity of Eero Saarinen’s original design with the requirements of the new functional program is prominent. The addition of the sixth floor and the rooftop pavilion raises questions about the extent of the new mass’s impact on the original proportions of the facade and the perception of the building’s overall volume within its urban context in the historic square. Furthermore, while the removal of the internal partitions from the embassy era aimed to revive the space under the concrete ceiling, it also erases the archaeological layers that documented the building’s previous functional phase. However, the technical effort involving the careful disassembly, restoration, and reassembly of over 4,000 original building components remains a procedure that preserves the material details and structural authenticity of the architectural heritage