22 To 25 Northampton Square, 11 Sebastian Street, And Attached Railings

A terrace of four houses, numbered 22 to 25 Northampton Square, along with the adjacent property at number 11 Sebastian Street, built around 1810. The houses are constructed of yellow brick in a Flemish bond pattern, topped with mansard roofs covered in Welsh slate and artificial slate. Each house has four storeys over a basement, with two windows on each floor. All window and door openings feature gauged brickwork heads.

The recessed entrance to the terrace is set under a round arch; Number 22 has a moulded doorcase with a modillion cornice and a fanlight. Numbers 23 to 25 feature reeded engaged columns, a modillion cornice, a fanlight, and panelled doors originally designed for the property. Number 11 Sebastian Street has reeded engaged columns, a modillion cornice, and a fanlight, although the fanlight appears to be a replacement.

The ground-floor windows are round-arched and recessed within a round arch. A stucco sill band runs continuously across the facade. First-floor windows are flat-arched and also recessed under a round arch, with individual iron balconies. Second-floor windows are also flat-arched. The original 6/6 sash windows remain in Number 23 (second floor) and Number 25, and in Number 11 Sebastian Street (first floor). An original rainwater head is located between numbers 10 and 11 Sebastian Street. The building has a brick dentil cornice and a parapet. Dormer windows are incorporated into the mansard roof. The area railings include urn standards and spearhead finials. Number 11 Sebastian Street was added to the listing on September 29, 1972.