The former home of the 4th Duchess of Northumberland in Mayfair is now available on the market.

Transformed by ultra-prime developer Luxlo, the lateral 2,334 sq ft/216.9m2 three-bedroom residence takes up the entire second floor at 10 Upper Grosvenor Street. The apartment is for sale for £9.5 million via Wetherell.

The apartment, once a meeting place for high society and political strategists, including Prime Ministers and a Foreign Secretary, has been completely modernised. It features a south-facing double reception room with sash windows, an adjoining dining room, and a state-of-the-art Boffi kitchen. There are three ensuite bedroom suites, including a principal with a walk-in dressing room and a marbled main bathroom.

The apartment features a well-planned layout with reception and entertainment spaces at the front at Upper Grosvenor Street, and private bedrooms at the back.

The double reception room has a large feature gas fireplace, a stunning ornate ceiling and Cerma Marfil marble flooring with a Brown Emperador marble border with an Oak wood floor perimeter, with contrasting wood finishes designed in a sunrise pattern.

Double doors lead into the adjoining dining room/second reception room which can seat 12 people and has statement marble flooring which echos the design of the floor in the main reception room. 

The long and wide marble floored inner hall leads to the fully fitted Boffi kitchen which has Gaggenenau appliances and Fumed Eucalyptus wood cabinets with satin brass edging. 

The three luxurious bedroom suites include the principal bedroom with Emperor sized bed with bespoke full-height velvet headboard, Oak wood flooring and built-in Oak wardrobes and a main bathroom featuring Bianco Eclipsia marble, a marble bathtub and a walk-in marble shower with adjustable body jets. The two further bedroom suites both have ensuite bathrooms finished in Butterscotch and Tundra white marble with walk-in marble showers with body jets. 

10 Upper Grosvenor Street was originally built in 1843-44 by Hyde Park builder James Ponsford, and designed by Mayfair architect Henry Harrison. It became the London residence of the 4th Duchess of Northumberland in 1881, serving as a venue for high society gatherings. Following the death of the Duchess, the property was modernised by Grosvenor Estate architect Edmund Wimperis.

In 1927 it was acquired by Lord Edward Stanley, a senior Conservative politician. Stanley, who played a role in pivotal events leading to King Edward VIII's abdication, and his wife hosted notable political figures, including two Prime Ministers. Post-WWII, the building was converted into apartments.

Peter Wetherell, Founder & Chairman of Wetherell commented: “This magnificent residence at 10 Upper Grosvenor Street has been the home of a Duchess and has hosted two Prime Ministers and a Foreign Secretary. This historically significant property has now been newly remodelled and designed by award-winning developer Luxlo into arguably the finest lateral apartment currently for sale in Mayfair. Luxlo are known for their superlative quality and exacting attention to detail when it comes to interior specification and design and they have achieved an outstanding level of presentation with this beautiful and spacious new Mayfair apartment. This luxurious residence is perfect for a couple or family wanting a London pied-a-terre in the heart of Mayfair just off world-renowned Grosvenor Square and on the doorstep of Hyde Park.”   

The apartment at 10 Upper Grosvenor Street is for sale with a guide price of £9,500,000 (133-year lease, approx). For more information contact selling agent Wetherell on Tel: +44 (0)20 7529 5566.

See more photos on 10 Upper Grosvenor Street building profile.