11, St James's Square SW1

No. 11 St James's Square is a terraced town house built in 1736 by Henry Flitcroft, with Benjamin Timbrell as the builder and promoter. The front of the house is stuccoed and has been altered, along with some of the interiors, by Robert Adam for Sir Rowland Winn between 1774 and 1776. The building features stucco-faced brick with a slate roof, standing four storeys high with a basement. It is five windows wide, with a three-window centrepiece. To the left, there is a porch with Doric columns added in 1877 by Trollope & Sons, who also rusticated the side bays, while only the centrepiece originally had a rusticated ground floor. The windows are recessed glazing bar sashes.

The three-bay centrepiece is highlighted on the first and second floors by a giant order of Composite pilasters, which were originally topped with Tower of the Winds capitals. A dentil entablature slightly projects over the centrepiece. The third floor features strip pilasters that articulate the centrepiece, leading up to a blind balustraded parapet with breaks in the cornice. A cast iron Rococo balcony was added by Trollope & Sons to the first floor, while the area railings, which date back to the 1730s, remain uniform with Nos 9 and 10.

Inside, the layout is similar to No. 10 but has been considerably altered. It retains several Adam friezes and cornices, although the ceilings are more likely in the Adam style from the early 1900s. The best-preserved feature is the staircase, which has stone steps rising around three sides of an oblong well, with galleries on the first and second floors. The staircase is adorned with a wrought iron balustrade decorated with lead castings and a mahogany handrail, though its design is not associated with the Adam style and may be late 18th century or Edwardian. The stucco work on the walls and the pendentives and arches of the dome are decorated in the Adam manner, while the Baroque cartouches in the dome itself may be original work by Flitcroft.