Carolyn Morse Ely wasn’t one for guests. When she commissioned architect David Adler to build her a sizable home in Lake Bluff, she asked for just two two primary bedrooms — hers and a guest room — situated at opposite ends of the house. There were also smaller rooms for servants. After five years, Ely, the only daughter of a steel magnate, sold the property in 1928 to DeForest Hulburd, president of the Elgin Watch Company. In the 1950s, Hulburd detached the north wing, moved it across the lawn, and sold it to a friend. Expanded and updated over the years, this severed section, located at 131 Moffett Road, is now on the market for $3.125 million.

In 2000, interior designer Athalie Derse bought the 6,000-square-foot snipped-off four-bedroom, four-bathroom house for her family. She redid windows and doors to Adler’s original designs and added her own touches, such as a terrazzo floor with a bronze inlay in a chevron pattern. The ground floor comprises two wings linked by a 38-foot-long gallery, anchored by a large family room with a fireplace and built-in bookshelves. The second floor is dedicated to the primary suite, with a fireplace in the bedroom and a bathroom featuring a freestanding tub, five closets, and a charming window seat.

In addition to an expansive island for food prep, the kitchen includes a fireplace, a dining area, and a lounging spot roomy enough for a sofa. And the dining room is less dark and buttoned-up than is usual for homes of this vintage, with a black-and-white checkerboard floor and French doors leading to the garden. Adler would roll over in his grave if he knew the Ely home had been truncated. But if he got a gander of this renovation, he might just sit up and smile.