21, King William Street

21 King William Street is a rare example of a Wealden house, likely built in the late 15th century, but significantly altered in the 17th and 18th centuries. The building has two storeys with attics and features two windows. It is timber-framed and plastered, displaying 18th-century small panels that are raised and roughcast, bordered by broad smooth plaster. The roof is made of concrete tiles and has a central chimney made of red brick, along with a gabled dormer from the 18th century. The windows are from the 19th century, with small panes; the ground floor has sash windows, while the first floor has casements. A 20th-century side entrance door is also present.

Originally, the house included a storeyed bay on the right that jutted out at both the front and back, a single-bay open hall recessed at both ends, and a probable service cell on the left that contained a cross-passage, which has since been demolished and replaced by No. 19 King William Street. This configuration would have created a Wealden-type elevation at both the front and back, a characteristic not found elsewhere in Suffolk at the time of the survey.

Inside, at both ends of the small open hall, there are beams at the first floor level that are moulded and embattled, with one tie-beam displaying similar mouldings visible in the hall. The studwork is widely spaced and tension-braced. The roof features a plain crownpost that is smoke-blackened in the hall bay. During the 17th and 18th centuries, the front wall framing of the hall and the lower wall beneath the jettied bay on the right were pushed forward to create a flush facade. Part of the rear jettied wall remains, incorporated within a 19th-century extension. Additionally, a first floor was added to the hall, complete with an internal chimney during the 17th or 18th century.