Passing through a series of owners in the 18th, 19th, and 20th centuries, the house had grown to 13 rooms by 1938, when it was purchased by Henry Sharpe and his sisters, Ellen Sharpe and Louisa Sharpe Metcalf. Additions by this time included a one-story parlor with a separate fireplace at the north end, a second lean-to with kitchen, bath and stair hall and two bedrooms, a one-story ell at the southwest corner, and a front hall and porch at the southeast corner.
Nonetheless, the Sharpe family valued the age and recognized the stone-ender characteristics of the house and commissioned Norman Isham, who had directed restoration efforts at nearby Arnold House in 1920, to investigate the structure and restore the house to its 17th century appearance.
Isham determined that the original house consisted of one-and-a-half stories with a rear lean-to and a steep gable roof. In plan, he found evidence of four rooms on the first floor, instead of the more typical one-room plan of other early stone-enders. Removing the later additions and baring the main block of non-original interior finishes, the house was rebuilt to reflect Isham's findings.
The plan consists of a great room and chamber in the main block, with a kitchen and second smaller chamber in the rear lean-to. Using a combination of salvaged and new materials to recreate the original appearance of the house, Isham also commissioned furnishings made from old wood to complement the architectural reconstruction.
Significant as one of the oldest houses in Rhode Island, the Clemence-Irons House also is important as a record of mid-20th century restoration ideas and methods. The house was donated to SPNEA, now known as Historic New England, in 1947, and together with the Arnold House, the Clemence-Irons House provides a rare opportunity to study the stone-ender in New England.