In 1692, John Turner II added a new north kitchen ell to the rear of the house (later removed but then restored in 1908-1910), as well as the famous "secret stairway" within the rebuilt main chimney. Circa 1725 he remodeled the house in the new Georgian style, adding wood paneling to the rooms and double sash windows. These alterations remain, and are very early examples of Georgian decor. Research at The House of the Seven Gables has shown that the kitchen ell, thought to have been added in 1692, was added in 1675; only a small brewing room addition was added in 1692. The House of the Seven Gables is the oldest surviving mansion house in Continental North America, with 17 rooms and over including its large cellars.
After John Turner III lost the family fortune, the house was acquired by the Ingersolls, relatives of Nathaniel Hawthorne. He was thus often entertained in the house while growing up, by his cousin Susannah Ingersoll. During these later years, gables were removed, porches replaced, and Victorian trim added. In Hawthorne's time, the house had only three gables, but his cousin told him the house's history, and showed him beams and mortises in the attic indicating the locations of former gables. (In those visits Horace Ingersoll also told Hawthorne a story of Acadian lovers that later became the basis of Longfellow's famous poem "Evangeline".)
In 1908, the house was purchased by Caroline O. Emmerton, founder of the House of Seven Gables Settlement Association, and she restored it from 1908-1910 as a museum whose admission fees would support the association. Boston architect Joseph Everett Chandler supervised the restoration, which among other alterations added back the missing gables. The reconstruction in some cases sacrificed historical authenticity in the interest of appealing to visitors, who naturally expected the house to match the one described by Hawthorne. Thus, for example, Emmerton added a "cent-shop" resembling the one operated by Hawthorne's fictional character Hepzibah Pyncheon.
Many interesting features of the original mansion remain, including unusual forms of wall insulation, original beams and rafters, and extensive Georgian paneling.
The Nathaniel Hawthorne Birthplace is now immediately adjacent to the House of the Seven Gables, and also covered by the admission fee. Although it is indeed the house in which Hawthorne was born and lived to the age of four, the house was sited elsewhere when he lived there.