No. 6 and Attached Railings

This is a three-bay, three-storey terrace house with an attic and basement, originally completed in 1790 and with 19th-century alterations. Designed by John Palmer and built by Charles Viner, it forms part of an incomplete development associated with St James's Square. The front elevation is limestone ashlar, painted at ground floor and basement level, with rubble and ashlar at the rear. The roof is a mansard of Welsh slate, built up to the third floor, with a coped gable wall and two ashlar chimney stacks, some featuring early clay pots.

The front has a symmetrical arrangement of windows. The first floor has three grouped plate glass windows with horns, set in splayed reveals and with a continuous stone sill and wrought iron balconette. The second floor has three similar windows without horns, in plain reveals and with a continuous stone sill. The ground floor has a two-over-two horned sash window to the left and a six-panel door with beaded and glazed panels, set within a moulded architrave, with console brackets and a moulded cornice. A single flight of steps, leading to a pennant-paved crossover, serves the entrance. The basement has an eight-over-eight sash window and a six-panel door, both with three steps under the crossover. A triple dormer is present on the roof. Additional features on the front include a timber bressumer, a stone band course, a moulded eaves cornice, and a coped parapet. The rear elevation shows a six-over-six sash window to the first floor, other windows are plate glass, and wrought iron balconettes are present on the ground and first floors. There’s also a one-and-a-half-storey ashlar extension to the basement. The interior was not inspected during the listing process.

Attached to the front are wrought iron railings with cast arrow heads on limestone bases. The house occupies land leased from Sir Peter Rivers Gay in 1790, with an underlease granted to Charles Viner. Marlborough Street forms one of the diagonal approaches to St James's Square.