HOBOKEN, N.J. — On summer evenings, the running path along the riverfront here is clogged with businessmen on smartphones tripping over dog leashes and joggers weaving through a stream of strollers. It had gotten even more congested recently as curious pedestrians congregated around a fenced-off parking lot on Sinatra Drive to guess the purpose of the structure being built inside.
“People have asked us if we’re building a waterfront bar,” said a worker, Steve Scribner. “As if Hoboken needs any more. Someone else thought it was a houseboat, or some kind of giant Porta-Potty.”
But even taking into account Hoboken’s love affair with happy hour, there was an urgency to the building process that seemed incongruous. Someone was always there hammering or sawing — and many of the workers seemed a little young for cocktails.
The compact, shoe-box-shaped mystery building is named Empowerhouse, and it is a superefficient, solar-powered house that will compete in theSolar Decathlon, an event sponsored by the Energy Department that will open on Friday on the National Mall in Washington. It was designed and built by architecture and engineering students from Parsons The New School for Design, the Stevens Institute of Technology and the Milano School of International Affairs, Management and Urban Policy.
Yet the group aimed to create a structure that would endure in a meaningful way after the competition results are in. Unlike the 19 other entries, Empowerhouse is destined to become a real home for a low-income family in the Deanwood neighborhood of Northeast Washington that will also serve as a model of sustainable housing for Habitat for Humanity.
This year, for the first time, houses in the competition are being graded on cost-effectiveness, as well as energy efficiency and attractiveness. The last winning house was a $2 million entry from Germany with an exterior completely covered in solar panels.
“They racked up extra points because they were producing power above and beyond what the house needed,” said Joshua Laryea, student project engineer from Stevens. “But who can afford a house like that and maintain all those solar panels? It wasn’t a place designed for living in.”
Joel Towers, the executive dean at Parsons, said: “We probably won’t be the shiniest box on the Mall, but a lot of the technology that’s needed for tomorrow’s housing is already available. The question we’re trying to answer is more social than technological — how do we actually bring these green solutions into neighborhoods?”
Empowerhouse tackles cost-effectiveness through “passive house” design principles, an international standard to minimize energy demand that is just beginning to gain traction in the United States. Passive houses are well insulated and nearly airtight, with 12-inch walls and triple-glazed windows, and they require up to 90 percent less energy for heating and cooling than an ordinary house. (They consume 40 percent less than a typical high-efficiency home.)
Such low energy consumption enabled Empowerhouse to have one of the smallest solar panel arrays in the competition, which helps keep construction and maintenance costs down.
For Habitat for Humanity of Washington, the Empowerhouse project is just the beginning of a new wave of sustainable housing. Once the house is moved to Deanwood, Habitat will work with the students and other volunteers to transform the 1,000-square-foot house — estimated to cost about $250,000 — into a two-family duplex of 2,700 square feet with an eventual estimated cost of $530,000. Two more three-unit passive town houses are in the design phase, and construction is scheduled to start in the Ivy City neighborhood of Northeast Washington in the spring.
Kent Adcock, president of the Washington affiliate of Habitat for Humanity, said that in the future, all construction originating from his group would be based on the passive house model — quite an achievement for a team of students, most of whom had never picked up a power tool before this summer’s construction project.
“We’re designers — most of us hadn’t really handled much more than an X-Acto knife before this summer,” said Jason Hudspeth, a student project architect and a graduate of Parsons. “X-Acto knives aren’t very handy when you’re trying to put up drywall or pour cement.”
While constructing a passive house costs about 10 to 12 percent more than Habitat’s current models, this upfront cost is more than offset by the near elimination of utility bills. For a comparably sized home in the Deanwood neighborhood, utility bills are about $2,300 annually, and with energy prices predicted to continue rising, over the course of a Habitat home’s average 25-year mortgage, a homeowner could save anywhere from $61,000 to $132,000.
“These savings could be the difference in that family advancing their education, or paying for child care, or even in investing for retirement,” Mr. Adcock said.
In June, his group is planning to host a conference for Habitat for Humanity affiliates from across the country to share what they have learned about passive house design and construction. Empowerhouse will serve as a model for an easily replicated, affordable, energy-efficient home for urban communities.
A more immediate concern was carefully taking apart what they had spent all summer putting together so that it could be moved to the National Mall for judging. The move took place last week.
“It took us so many tries to get everything right,” said Mr. Scribner, a recent architecture graduate from Parsons. “It’s kind of nerve-racking to have to take it all apart. It’s going to be one heck of a 3-D puzzle to put back together.”
By JOANNA M. FOSTER