A £25 million Mayfair mansion townhouse where Jackie Kennedy stayed is on the market through joint luxury estate agents Wetherell and Knight Frank. The rare home has the potential to be transformed into an imposing family home, with income-generating commercial ties.
The sale represents one of the most significant trophy home listings of 2026 in a postcode with a historic undersupply of super prime, original family dwellings.
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Although turnkey super prime homes make up the bulk of interest in the ultra-luxury London real estate sectors, this rare listing will appeal to buyers who value scarcity, historical context and redevelopment optionality over polished, ready-made luxury in Mayfair.
Originally constructed as a grand residential dwelling in the early 1900s for wealthy American businessman James Monro Coats of the Coats-Auchincloss dynasty, 26 Upper Brook Street was converted for office use in the mid-1950’s and used, most recently, as the Mayfair address of the Bank of Africa.
It was here that a young Jackie Kennedy and her sister stayed in the summer of 1951 while on a tour of Europe, visiting their stepfather’s cousin Hugh D Auchincloss Jr in London.
Available for the first time in 30 years, the five-storey, £25,000,000 ($34,000,000) townhouse presents a rare opportunity for a buyer to convert the super prime Mayfair residence and configure it for private, needs-based use, say the agents.
What makes 26 Upper Brook Street compelling is not just its development potential, but its ability to add significant investment value – something increasingly sought after as ultra-prime buyers look for assets with income-generating potential.
According to the agent listing the property, the townhouse might be worth an estimated £55million ($75m) after redevelopment and also comes with commercial premises.
While some super prime buyers might value finished stock, this confidence in redevelopment value capital will appeal to more investors putting down long-term roots in the capital, especially those exploring additional incomes via mixed-use assets.
While full planning permission has yet to be secured, Westminster City Council has given positive feedback regarding the building’s potential residential development, according to a press statement.
A look inside a storied Mayfair grand dame
After demolishing the original dwelling, the residence was designed to be a grand London home for the wealthy US 19th and 20th-century “new money” dynasty, which combined Scottish heritage with American industrial success in textiles, trading, and finance.
Exteriors are dressed in a handsome Portland stone façade, traditional Mayfair architectural vernacular, with large bay windows and a gable bearing the Auchincloss-Coats family crest.
The property offers 11,494 sq ft of living space across five floors, with upper and lower garden terraces connected via a stone staircase.
Designed by architect of the rich and famous du jour Arnold Bidlake Mitchell, with a vast real estate portfolio of illustrious properties to draw from for inspiration, including Jackie Kennedy’s childhood home in Newport, Virginia, no expenses were spared in dressing the grand spaces with lavish trimmings and design features of the era.
High-end accoutrements were borrowed from popular Old New York-style Gilded Age elements and Edwardian-era high society design must-haves.
Thickly dressed, maximalist interiors wear opulence and wealth on their sleeves, crammed with breathtaking features that marry showy displays of wealth, characterised by heavy, dark wood floors, intricate ceiling and wall plasterwork, large stone fireplaces, French Rococo revival features and clean lines of Edwardian-era proportions.
Emphasis on natural materials translate to liberal use of wood and marble – including grand Corinthian columns – throughout the luxury dwelling.
CGI-rendered images reveal celebrated original features updated for modern tastes of ultra-high-net-worth future owners.
Conversion back into a family residence
Agents say that multiple internal configurations to suit the needs of ultra-high-net-worth owners are possible, with floors potentially connected by an internal passenger lift.
Beyond the grand entrance hall and staircase agents believe the ground floor will lend itself well to a family kitchen, breakfast room and reception rooms.
On the first and second floors above those marketing the property suggest two interconnecting reception rooms plus a principal bedroom suite with dressing area, bathroom and study/day room. The third and fourth floors could accommodate two or three en-suite bedrooms each.
On the lower ground floor there is potential for a staff bedroom or living room, club room, a catering kitchen, wine cellar, and a large gym with a pilates exercise floor.
Moments from prime London address Park Lane, adding another upscale dimension to this breathtaking Mayfair townhouse is the front row view of Hyde Park.
In addition, the property is offered with a mews house at the rear providing 2,434 square feet of prime commercial office space. This will remain commercial, which may provide tax advantages. Internally there is also room for potential staff dwellings, complete with a living room, bedroom, bathroom and kitchen.
Combined, the two dwellings create a rare combination of private residential and professional workspace within a single Mayfair holding.
Peter Wetherell, Founder and Chairman of Wetherell, says: “The provenance of this Mayfair mansion building offering views onto Hyde Park is outstanding.
“The beautiful and ornate interiors of the house reflect that vast wealth and now a discerning buyer has the unique and exciting opportunity to bring this landmark building back to life.”
Billionaire buyers of 26 Upper Brook Street
Who might be the new owners of 26 Upper Brook Street? Ultra-high-net -worth families seeking a London base, billionaire developers, royalty or those wilth political connections might be interested in the estimated £55million ($75m) post-conversion mega-project.
Or, alternatively, the grand space might remain a commercial use property serving as a new embassy or boutique headquarters for one of the many top hedge funds that cluster around Mayfair.
According to a new report by high-end agent Beauchamp Estates, billionaire buyers in London are increasingly turning to best-in-class properties on larger plots with health and wellbeing facilities, or integrated lifestyle services (concierge, gyms, pools and security). Branded and serviced residential developments continued to gain traction in 2025.
The report reveals that interest in refurbishment projects and off-plan purchases declined sharply in 2025.
Prime Central London postcodes will lead demand as supply lags with ‘addresses of choice’ for the super-rich Belgravia, Knightsbridge – both winners in 2025 – and Mayfair seeing the highest interest among high-net-worth buyers looking for a London base.
Interiors images rendered by Casa E Progetti.
For more information: https://www.wetherell.co.uk
