Numbers 1 to 32 (Consecutive) and Attached Railings

Numbers 1 to 32 Thornhill Square comprise a terrace of 32 houses built around 1836 to 1842. The houses are constructed of brown and yellow stock brick in a Flemish bond pattern, with stucco applied to the basement, ground floor, and cornice. They have pitched slate roofs and party-wall stacks. The terrace is symmetrical and curved in plan.

Each house is three storeys high, with basements and some attics, and generally has two windows on the front elevation, with numbers 1 and 32 each having three. The ground floor is banded with stucco and features segmental arched sash windows, some with margin lights. A sidehall entrance is characteristic, leading to a staircase. Steps lead to a square-headed doorway on the left-hand side, with a panelled door flanked by plain pilasters supporting a corniced head. A rectangular overlight with simple glazing bars sits beneath a rosette frieze and console bracketed cornice. Numbers 1 and 32 have a stucco portico.

The upper floors are of brick with a plain sill band. The first floor has blocks of three houses with a pedimented three-light sash window, with the central window of each block featuring a segmental pediment; these alternate with recessed blocks of four or six houses with two architraved windows each. First-floor three-light windows are fitted with cast iron balconies, while others have cast iron window guards. The second floor features single three-light architraved sash windows divided by pilasters and with apron panels. A stucco cornice is present, with blocking courses on numbers 2, 7, 8, 16-18, 20-22, 25, 29-32. Some attics have dormers. Original iron area and porch railings are present at numbers 1, 2 and 32.