The house appeared to have everything: A prime Tribeca location. An architecturally distinctive exterior. Impressive pedigree. An expansive 6,750 square feet of interior space, with ceilings as high as 15 feet, plus a 650-square-foot roof terrace. Even a private garage. And yet, something was amiss.

“The quality of construction just wasn’t commensurate with the history of the home, or representative of the people that intended to make this their primary residence,” designer Nate Berkus recalls thinking on his first walk-through of the recently renovated and expanded structure. While touring the property with prospective clients, he quickly realized “the redo of this building wasn’t going to cut it.”

“I love architectural salvage,” Berkus says, pointing to the pair of hundred-year-old French doors in the entry hall.…