12 William Street including Iron Railings to Front Area

12 William Street is a house in a terrace row, constructed with unpainted stucco and featuring a slate roof with stone end stacks. The building has two storeys and is double-fronted, showcasing an ogee eaves gutter supported by paired brackets. It includes hornless 12-pane sash windows with painted slate sills and an applied slate plinth. The central entrance consists of a 6-panel door with an overlight, set within a Roman Doric doorcase that has two half columns, entablature blocks above, and a pediment. In front of the house, there are low iron railings with a top rail and spearhead dog-bars. The adjacent house, No 13, was formerly similar but has had alterations to its windows.