Yes, it’s big—especially by Manhattan standards, where closets often pose as bedrooms and bathtubs can be found in kitchens. And yes, it’s grand—although its owner, architect John Petrarca, has some sage advice about scoring designer finishes at bargain-basement prices.

But before you dismiss this five-story, 6,000-square-foot home and office space (4,000 square feet are for John and his family; 2,000 are for his five-person office) in New York’s historic Tribeca neighborhood as too big and too grand to be green, consider the innovation and imagination that went into lessening this urban infill project’s impact.

In the early 1980s, when Tribeca (short for ­Triangle Below Canal Street) was still an urban wasteland full of derelict, vacant buildings, John and his wife, Sarah Bartlett, bought a 1,600-square-foot, four-story house on Reade Street, which they renovated themselves. “We did all of the plumbing, heating, and carpentry ourselves,” John remembers. “And Sarah mixed about 100 bags of cement.”

The couple also bought the industrial loft building next door and, a few years later, the former butter factory next door to that. Eventually, he and Sarah sold the home they had renovated and went to work on a new home as well as four speculative townhouses. And in the process of developing his Reade Street empire, he’s also created what he calls “the greenest house in Manhattan”—a castle of sorts—for his family.

They chose limestone and oiled wood floors, low-toxic paints, natural linoleum, and natural wood finishes that wouldn’t outgas harmful chemicals.

Steel, foam, and concrete

John, Sarah, and their two children, Ian and Emilia, live in the tallest building ever to be built using insulated concrete forms (ICFs)—and the first of its kind in the city. These structural forms, made of polystyrene foam insulation and ­concrete, were chosen for their superior insulation qualities as well as their ­thermal mass—which means significant energy savings compared with wood or steel-frame homes. John was also drawn to the material because he could attach the wood and Sheetrock walls directly to the Styrofoam, leaving no air space or cavities, which contributes to their ­superior insulation and, perhaps just as important in New York, harbors no roaches or rats.

Pioneering the use of this material in an urban setting was no small task. “There’d been no history of its use here,” says John, adding that he and city building officials “argued and argued and argued” about the building ­material. The city eventually sued John, but he won the right to use it.

His next hurdle was dealing with the labor unions, who couldn’t agree on whose jurisdiction ICFs would fall under. Who should be in charge here? Masons, concrete workers, carpenters? The carpenters won out; concrete workers assisted.