Architect Kevin Kennon knew he had to tread lightly when he started work on 157 Hudson Street in TriBeCa. The long history of the place is not so much the story of a building in brick and wood as that of a mirror reflecting changes in the way New Yorkers use their city.

“It was one of those hidden gems in TriBeCa that’s got this great history,” Mr. Kennon said in an interview. “It had been painted over and looked pretty distressed, and I bet a lot of people didn’t even notice it. It sure cleans up nice, though.”

The structure was built in 1866 and sold four years later for $24,750 cash. According to newspaper reports at the time, “was considered very cheap at the price” because it lay “directly opposite the new Hudson River Railway depot.”

It first served as a stable for the American Express Company, back when their horses competed with the postal service to carry packages and bank notes to the expanding American West.

In 1898 the building was expanded and received a new façade, and for most of the 20th century it was a manufacturing warehouse before opening as the music venue Rock City in 1980.

A series of nightclubs followed, none lasting very long, and each eventually chased out by the conversion of the “Lower West Side,” then a light manufacturing neighborhood, to “TriBeCa,” a tony residential one.

The developer Kevin Moore bought the building for $18 million in 2004 from the family of the artist Alexander Calder, whose daughter and grandson lived on the upper floors. The original 60,000 foot building will now receive an additional 17,000 square feet of space and be divided into 17 multi-family loft apartments and two penthouses. Mr. Moore expects them to go for around $1,400 a square foot. The project is scheduled for completion towards the end of the year.

Mr. Kennon, the architect, restored the original pine joists, stonework and piping in his renovation, and added a 4,500 square foot duplex with transparent glass cubes on the exterior.

“Most penthouse additions are not very skillfully done,” Mr. Moore, who has an architect and developer, has collaborated on several projects with Mr. Kennon, said. “The whole building acts a plinth to the penthouse on the roof. People who look down on this will be rewarded by a very thoughtful piece of architecture with great landscaping.”

Mr. Moore said such additions were necessary to make the project financially viable, and he originally proposed a larger addition, but it was rejected by the Landmarks Preservation Commission.

“Landmarks has approved some very unfortunate additions, so it is only natural that they would recoil a little bit,” Mr. Moore said. “There are no specific guidelines with landmarks, so it’s always a challenge to know what you can and can’t do.”

The project received some pushback from local residents and preservationists as well.

“The zoning was changed to allow for towers so people started plunking these additions on that got weirder and weirder,” the executive director of the Historic Districts Council, Simeon Bankoff, said. “You do something like that and you mess up on the streetscape something fierce. You beat up on the whole texture of TriBeCa. We do not encourage this.”