Builders Report Progress on Zero Energy Homes - 2/9/2004 - House Energy Efficiency

Builders Report Progress on Zero Energy Homes

During an educational seminar at last month’s International Builders’ Show in Las Vegas, four builders shared their experiences working on these cutting-edge homes.

Centex Homes recently completed its first ZEH home in Livermore, CA. According to project manager Jeff Jacobs, making such a venture a success requires support from management, manufacturers, suppliers and subcontractors.

“Our home used solar water heating and photovoltaic cells and was developed using standard construction techniques,” said Jacobs. “Our process consisted of selecting the right home, one with the necessary attic and roof space for solar panels. We added two large gable vents to bring in nighttime air in the evening. The system, developed in conjunction with our subcontractors and field managers, nearly eliminated the need for compressor cooling in the summer.”

The single-story prototype home is wired so that all systems can be monitored and includes more than 50 sensors to provide data for a cost-benefit analysis.

The photovoltaic system produced 102% of the home's electrical needs. However, Jacobs acknowledged that not all of the home's technological innovations were cost-effective, and he called for continued government funding to encourage new breakthroughs.

Combining renewable energy and solar energy with highly energy-efficient products, Robb Aldrich, an engineer with Steven Winter Associates in Norwalk, CT, designed a modular ZEH home in New York City.

“Site and orientation have a definite impact on energy production,” he said, noting that a typical home that is oriented from north to south consumes far less energy for heating and cooling indoor air than the same home turned at a 90-degree angle.

Aldrich said that solar panels on an affordable home geared to buyers earning 80% of the area median income cut the average monthly electricity cost from $66 to $26.

In Las Vegas, Pardee Homes recently constructed a 5,300-square-foot ZEH home, equipping it with a solar water heating system, photovoltaic systems, fluorescent halogen lighting, insulation in the ducts, a highly efficient air-conditioning system, Pella windows and insulation close to R-40 (as opposed to R-21 normally used).

“This home’s owners are extremely proud of their ZEH status,” said Rob Hammon, principal of ConSol, an energy consulting firm based in Stockton, CA.

In order to further advance the technology, Hammon added that new research is needed to integrate solar energy into homes and to bring costs down.

In Tucson, John Wesley Miller Companies' ZEH home — which is part of a 100-home infill development — utilizes solar photovoltaic and water heating technology.

“The heating and cooling bill for our typical 2,000-square-foot home is less than 90 cents per day,” said Miller. On hot days, the home owners really get a kick out of watching their electric meter run backwards.”

In order for ZEH to take hold in the marketplace, the panelists said:

• More research and development is needed.
• Federal support for the initiative must continue.
• The pending congressional energy bill that includes builder and consumer incentives should be passed.
• Training and education should be expanded.
• Sound cost/benefit analysis must be developed.

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