Twenty Grosvenor Square

A redevelopment of the former European Headquarters of the US Navy in the heart of historic Mayfair, Squire & Partners’ design revives a historically significant building to establish a new contemporary residential address befitting its prestigious location. Twenty Grosvenor Square comprises 37 apartments and penthouses with resident amenities including a 25m swimming pool, spa, cinema, garden library, wine cellar and business suite.

The removal of an existing central bay to North Audley Street, within two existing bookends, clarified the orientation of the building and established an identity with a contemporary setback elevation featuring a porte-cochère entrance.

Crafting traditional materials of brick, glass, stone and metal with modern technologies such as CNC machining, waterjet cutting and laser cutting has created an intricately detailed elevation drawn from the rich history of the area. Bespoke façade details include contemporary pilasters, fluted stone, projecting bay windows, linear balconies and ornate patterned metalwork.

The existing elevation to Grosvenor Square has been refurbished and layouts amended to establish garden views from reception rooms and master bedrooms. A new slate-clad stepped mansard enhances the penthouse levels, and improves the aspect across Grosvenor Square and the surrounding Mayfair roofscape.

From the sweeping entrance, a sequence of internal spaces connects to a garden library and courtyard to create a seamless transition from Grosvenor Square. A double height volume creates a dramatic entrance space, and connects to the amenity levels below via a grand staircase with a feature lighting installation by Czech glass artists Lasvit.