For 15 years architect David E. Cohen has tried to persuade his clients to let him design earth friendly, energy-efficient buildings. Now he will not only “put his money where his mouth is,” but also “put his home where his heart is.”
During August he will supervise the construction of the shell of his own new, environmentally friendly home at 135 Terhune Road in Princeton, using a system of structural wall panels. The eight-inch thick panels consist of a sandwich of compressed straw with an engineered wood panel skin.
“Being green isn’t about sacrifice or eating granola any more,” says Cohen. “It’s about doing things in a different, more ecologically sound way. The next biggest wave in business is going to be in green products.”
The project is billed as “the first green house constructed in central New Jersey.” Cohen has promised to log the progress on his website (www.decarchitect.com). Thomas Giovannoli, of Thomas Design Associates in Pennington, is the construction manager, and Dennis S. O’Neill, of Princeton Design & Installation, will do the renovation and construction.
Cohen is a native of Rochester, New York, where his father was a doctor and his mother a children’s librarian. He graduated from Harvard, Class of 1980, earned a master’s in architecture from the University of Virginia, worked at CUH2A, and was a partner at Michael Landau Associates.
A confluence of events helped Cohen to decide to strike out on his own in 2002. He received a small inheritance from an aunt, and learned about several projects that were “too small for Landau but just the right size for a start-up company” at about the same time. In addition, his new home was in the planning stages, and he thought that the “slow period” of starting up would be the perfect time for working on his own project.
He started planning the project about 10 years ago when he found the perfect property with a duplex, where he and his family could live while the new house was built, as well as an additional lot that has been subdivided. The property on which he is building consists of .42 acre, and a developer, Roman Barsky, owns the adjacent .48 acre. But, as is often the case in building projects, things moved slowly, and it wasn’t until March of this year that he was able to break ground.
In the meantime, the house has undergone a few revisions, as new technologies have come on the market. One change has been to downsize the house a couple of hundred square feet to 2,900. “Smaller is more ecologically sound,” he explains.
The house has also become more modular, Cohen calls it the Lego House because most of the basic structure arrived in pieces on trucks. “There are more than 100 separate modular pieces,” he says.
The finished house will use 80 to 90 percent less lumber than a conventionally framed house but will provide almost twice the insulation, says Cohen. The modular panels for the walls, the roof, and the subfloor are made by Agriboard Industries of Wichita, Kansas. The ready-to-assemble panels come with all openings — doors, windows, electrical, plumbing and venting — pre-cut, saving time and labor at installation.
Made of compressed straw with a wooden shell similar to strand board, these panels are more fire resistant than wood, have a higher insulation value, and low sound transmission levels. Because the panels require no interior glue and have no formaldehyde, they are non-toxic. And since it only takes a season to grow straw, versus several years or even decades to grow a tree, the product is “highly renewable and ecologically friendly,” says Cohen.
Other “green” features:
Radiant hydronic heating: A hot-water based system that uses heating elements in the home’s floors.
“Traditional” cooling strategies. Cohen’s home will have no air conditioning, but he still expects to stay cool in the summer by relying on such time tested strategies as an attic fan, deep overhangs to shade the home, porches on the southern side of the house for further shade, and sleeping porches attached to every bedroom.
Fiber-Cement siding: Manufactured by the James Hardie Company, it looks just like wood, says Cohen, but is actually made of cement and recycled newspaper
Cork floors. Cork is a more renewable resource than hardwood, Cohen explains, because the trees are not cut down when the cork is harvested. In addition, the material that he will use is recycled from the waste products of a manufacturer who makes corks for wine bottles.
Compressed cornstalk cabinets: for kitchen and bath, covered with a wood veneer, will improve air quality.
Compact fluorescent light will be more energy efficient than incandescent lighting.
No formaldehyde. Because fewer adhesives are used, and none with formaldehyde, the home will have healthier indoor air, Cohen says, with none of the problems associated with releasing gas, or “outgassing.”
Cohen is still considering whether or not to install a solar energy system. New Jersey is one of the best places in the country to install solar energy systems right now, he says, because New Jersey has a large number of sunny days, and the state government is currently offering substantial rebates for installing solar systems.
He is also considering a solar hot water system, which could be boosted on cloudy days by the boiler from his heating system. Cohen doesn’t yet have a bottom line on the difference in costs in “green building” versus traditional building.
Using traditional methods, a home of similar size would cost between $200 and $250 per square foot. He estimates his home will cost about 25 percent more, but acknowledges that the costs are lower because he is acting as his own general contractor.
Nevertheless, he hopes to save about 50 percent on his energy costs, making the long-term savings considerable. And while some of the building materials are more expensive, the modular construction means shorter installation time and lower labor costs.
The wall, roof and subfloor panels arrived on July 14, and Cohen expects it to take only about two weeks until the basic exterior structure is in place. He plans on the exterior being completed by the end of August and moving to interior finishing in September. Move-in is scheduled for November.
Once complete, Cohen hopes his home will be a model for others who want to “go green,” he says. “When people see that green is not about sacrifice and imposing a moral but unpalatable lifestyle, they will be more interested,” he adds.
DEC Architects, 149 Terhune Road, 609-252-9477; fax, 732-783-0310. www.decarchitect.com