Califon, New Jersey

advice, guidance, support, results

Asdal Builders: Making Zero Energy History

Near the hamlet of Califon in the northwest corner of New Jersey, Bill Asdal has opened an historic bed and breakfast. The Raritan Inn at Middle Valley, a 4,000-square-foot, five-bedroom Victorian, dates back to the late 1800s and is located on a 24-acre property once owned by the king of England. But that’s not the only reason this B&B; is historic.

Asdal, the owner of PATH Partner Asdal Builders of nearby Chester, made the property noteworthy with a remodeling job of unequaled proportions. With a helping hand from the National Association of Home Builders (NAHB) Research Center, Asdal has transformed a dilapidated property-which also includes a 4,000-square-foot barn, shed, and garage-into the nation’s first zero-energy remodel, according to NAHB engineers. Retrofitted technologies include photovoltaic roof panels, an active solar hot water system, and geothermal heating and cooling. “The core of the mechanicals is really where the technology comes into play,” Asdal says.

The dilapidated shell of what would become the Raritan Inn

The Raritan Inn may be the first zero-energy remodel in the United States.
and after.

However, the first step in retrofitting the main structure was to get it into habitable condition, which was no easy task. “The house had been vacant since the late ’70s, almost 30 years,” Asdal says. “When we bought it, it had been vandalized and was really in shambles.” The remodel included adding a new roof and floors, as well as rebuilding and repairing walls.

With so much work to do, energy-efficiency could have been an afterthought. Instead, Asdal made it a priority. “We took the perspective of a whole-house approach for energy efficiency systems, instead of looking at it piecemeal, as many remodeling projects might do.”

The fact that this house was deteriorated actually made the whole-house approach a bit more feasible. Asdal was doing so much renovation, it was more cost-effective to simply replace some systems, rather than retrofit them, says the Research Center’s senior research engineer, Joe Wiehagen. Wiehagen and his fellow engineers provided Asdal technical advice through the Existing Buildings Program of Building America, an initiative of the U.S. Department of Energy.

Asdal and the engineers started to look at energy savings through wall and ceiling insulation. The existing structure had no insulation whatsoever, so anything was going to be an upgrade. To insulate the interior walls, they opted for dense-pack blown R-15 cellulose. The NAHB engineers also recommended installing double-pane windows with hard-coat, low-E film, which allows more solar heat while keeping in more heat. The result is insulation three times greater than that used on single-pane windows. To ensure there were no air leaks, subcontractors then caulked the window frames to the framing. They also glued the interior wallboard to the framing, sealed the sill seam and band joist areas with spray foam, and paired that foam with drywall adhesive at floor and wall penetration points. As a result, the house has an air exchange rate of .25 per hour, which is a quarter of the rate before the insulation. “We are seven times tighter than a comparable house,” Asdal says.

Asdal also took a unique approach to the pipes. “There is no copper in the building,” he says. “Instead, we have runs from a manifold plumbing system to every fixture, so there are no shutoff valves.” Those waterways consist of 3/8-inch flexible plastic pipeline, called PEX. By using a smaller supply line than the usual 1/2-inch pipe, a home-run plumbing system wastes less water than a traditional system. Using plastic lines also means major labor savings because there is no soldering and there are no elbow joints to install.”

It also turned out the property was perfectly situated for using renewable energy technology, while also being located in a high-cost energy area where rates can reach 14 cents per kilowatt per hour (kWh). “In the beginning, we weren’t really designing this as a zero-energy project. In fact, we were doing an energy-efficiency retrofit. Using renewables was not one of the first items on the list since they tend to be fairly expensive,” Wiehagen says. “However, the property is in a good location for solar and geothermal. So once, Bill got the state’s financial incentives in place for the renewable energy, it made sense to go for zero energy.”

The installation of an innovative HVAC system provided Asdal with significant energy savings. A closed-loop geothermal system-also known as a ground source heat pump-was chosen because of the property’s large size and high water table. Engineers estimate the system will reduce heating and cooling energy by 50 percent. To further reduce leakage, the system’s air ducts, compressor, and air handler were placed in conditioned space inside the cottage rather than in the unconditioned attic. This decision prevents the loss of approximately 20 percent of the heat, engineers estimate. Asdal also likes the fact that the system is quiet.

Engineers suggested Asdal go a different route for the water heating. A 32-square-foot solar energy collector on the cottage roof supports the hot water system, while an electric tankless water heater provides on-demand hot water consistently at 125 degrees Fahrenheit.

The hot water system is not the only use of solar power. Asdal also installed an extensive photovoltaic system, placing solar collectors on the southwest-facing roofs of the cottage and garage. The systems generate an estimated 9,000 kWh per year, which is sufficient for the entire property. Furthermore, the state’s Clean Energy Program (NJCEP) offers up to a 70-percent rebate for installing solar photovoltaic systems. “New Jersey has a very extensive incentive program in place for photovoltaic energy,” Wiehagen says. “Being able to participate meant his costs would be greatly reduced-in fact by over half.”

In the end, the Raritan Inn is designed as a zero-energy home because it makes economic sense. “Without a viable business, all you have is an interesting zero-energy experiment that falls on its face,” Asdal says. And when the right property converges with costly energy prices and a strong state renewable energy program, the setting is perfect for creating a zero-energy remodel-and making a little bit of history.

Editor’s note: The Raritan Inn opened to guests Memorial Day 2006.

Leading the way

Let's build a better world together

Project planning

Design expertise

Great qualifications

Nullam vestibulum finibus sapien, id consequat mauris tempus auctor.


90 Newport St., Natick, MA 01760

83 Taylor Street, Kings Mountain, NC 28086

22 Birch Hill St., Villa Rica, GA 30180

Support requests

Nullam scelerisque leo felis, quis congue mauris tristique in. Suspendisse pulvinar, felis eu facilisis mattis, turpis odio luctus nisi, et ultrices velit enim quis lacus.

Request a quote

[Insert your contact form here]


Vivamus vehicula dictum elit at bibendum. Etiam finibus eros ut urna auctor ullamcorper. Sed at erat eget nisl rutrum ultrices sed eu ex.


Sign up to receive the latest news and trends from our company.

More questions? Get in touch