In the fall of 2006, Denis Carpenter approached the New Jersey chapter of the American Institute of Architects with a challenge: Was there an architect, he asked, willing and able to design a house to fit the tiny, weed-strewn lot he had just bought in a down-on-its-luck section of Jersey City, New Jersey?

The house had to be energy-efficient and easy to maintain, he said. It had to be built with concrete and include a cat door for Miska, his five-year-old Siamese mix. And the entire project had to be done for $250,000 or less.

Carpenter is, by his own admission, “not your usual customer” for a custom-built house. A former professional oboist and public-school science teacher, Carpenter, 56, draws a modest salary as a file clerk for a pharmaceutical company. Two well-timed real estate transactions left him with a little money to spend, so he paid $45,000 for a 1,300-square-foot lot next to a derelict public basketball court in Jersey City’s Bergen-Lafayette neighborhood, far from the city’s gentrifying downtown and waterfront.“I got this idea to build a house,” he says. “I don’t know where it came from. I wanted a little more room, because I had no room for guests.”

A copy of Carpenter’s request made its way into the email inbox of Richard Garber, who runs the Manhattan firm GRO Architects with his wife, Nicole Robertson. Garber and Robertson, who live near the Hudson River in Jersey City’s Paulus Hook neighborhood, jumped at a rare chance to work on a project so close to home. They drafted some preliminary drawings and sent them to Carpenter, who hired them almost immediately.

“I had gotten some names, and a few told me, ‘No, I won’t build for under $450 per square foot,’” Carpenter says. “And I ended up with Richard and Nicole. They seemed very excited, they lived in Jersey City, and they both taught. They just seemed like  the right people.”

The size of Carpenter’s lot—just over 22 feet wide and 56 feet deep—presented a serious challenge, but his short list of requirements also left the architects plenty of room to experiment with different designs, layouts, and finishes.

“Denis didn’t have any preconceptions about what he wanted the house to look like,” says Robertson, 37, an adjunct professor of architecture at Columbia University and Barnard College. “He wasn’t someone who came to us and said, ‘Oh, I want a Tudor house,’ or something like that. He had more performance-based requirements. He wanted it to be environmentally sustainable. He had a material requirement of concrete and a budget of $250,000 or so, which he was very clear about from the beginning. And that really set the parameters for the project. For us, that made it a lot of fun.”

Carpenter wanted an open layout for the main floor, where he expected to spend most of his time. So Robertson and Garber, 38, an assistant professor of architecture at the New Jersey Institute of Technology in Newark, started with a split-level design, stashing both bedrooms and the bathroom in the basement. Upstairs, they used three different ceiling heights—12 feet in the kitchen, eight feet over the entrance vestibule, and 18 feet in the living area—to define distinct spaces without building walls to separate them. Their design called for a 72-square-foot cantilevered deck to be built off the kitchen, offering a view of the Statue of Liberty in the distance.

The architects ran into the first of several obstacles early in the process when it became clear that they would need “a slew of variances,” as Garber puts it, from the city’s zoning board. Carpenter’s property was only about half the minimum lot size. More critically, Garber and Robertson needed to find a way around a requirement for a 30-foot rear setback, which would have shrunk the footprint of Carpenter’s house to an unworkable 378 square feet.

Garber and Carpenter met with Claire Davis, the city’s supervising planner, and Viola Richardson, who represents the neighborhood on the city council, to assuage their initial concerns that the building’s footprint was too large for the lot and that its concrete-and-cedar facade would clash with the older clapboard row houses on the block. With their support, the project won unanimous approval from the zoning board.

The insulated concrete panels that Garber and Robertson used for the exterior presented another set of problems. Their initial plan to pour the concrete  on-site proved too expensive and labor-intensive, so they embarked on a long, frustrating search for a company that could cast the panels in a factory, truck them to Jersey City, and assemble them on the lot. After a few false starts, they focused their efforts on Superior Walls of South Jersey (now North-east Precast), a Millville, New Jersey, company that specializes in prefabricated foundation walls.

“We got in touch with them and described the project, and they were just, like, ‘No way. Absolutely no way,’” Garber says, laughing. “But we were really convinced they could do it. We made an argument that we were determined to put the time in to work out the details to collaborate with them. It wasn’t something where we were just going to give them the plans and say, ‘Figure this out.’ We established a relationship with them where they were really part of the process of sorting it out.”

“We just kept on bothering them, basically,” Robertson says. The company’s owners relented and then threw themselves into the project. The 18 panels—rectangular, triangular, and trapezoidal, many with apertures for windows—were delivered to the site and hoisted into place with a crane over three days in late October and early November 2008.

Radiant heating coils embedded in the concrete basement floor and beneath the bamboo floor on the main level keep the 1,360-square-foot house warm in winter. The awning-style windows stay open in the spring and summer months, creating a draft that, with help from a pair of ceiling fans, compensates for the absence of an air-conditioning system. A 140-square-foot loft above the living area opens onto a small bed for a green roof that Carpenter plans to plant with sedum and blueberry bushes.

The pitched roof, which faces south and angles 30 degrees, houses a 260-square-foot solar array. Carpenter receives monthly credits from his utility company for surplus energy that he sends back to the grid. Garber estimates that the system, which cost $8,000 after tax incentives, will pay for itself after about five years.

With money running short, Carpenter found creative ways to save. Instead of buying new kitchen cabinets, he paid $300 for a set of white Republic Steel cabinets from the 1950s that he found on Craigslist, and covered them with a new black Formica countertop. The rear patio was built with 500 bricks that Carpenter salvaged from an old foundation unearthed during the excavation process. Construction was completed in August 2009 for about $252,000, just $2,000 over Carpenter’s initial budget.

Cedar-slat rain screens, mounted on the front and rear of the house, soften its appearance. (“Putting a concrete bunker in a neighborhood like this would send the wrong message, I think,” Garber says). The building’s facade was conceived as a modern riff on a two-family building down the block, and the house doesn’t clash with the other structures on the street so much as it complements them by putting a 21st-century spin on the venerable city row house. Garber and Robertson have come to see the house  as a model for urban infill redevelopment—a system that can be “mass customized” for specific settings while leveraging the cost savings that go along with the use of prefabricated components.

For Carpenter, though, the house isn’t a system or a concept. It’s home. The light-rail stop where he catches a train to work is a short walk across the basketball court and down a hill, “past all the weeds and the garbage,” he says. The house may not quite have the utilitarian “warehouse look” that Carpenter initially said he wanted, but it is open, airy, and comfortable, and his utility bills are low. His music caroms off the concrete in a pleasing way, and rosemary and sage from his garden add flavor to his meals. And Miska comes and goes as she pleases.