Preliminary findings from a study conducted by McGraw-Hill Construction and the U.S. Green Building Council (USGBC) note a strong demand for sustainable housing at all income levels, even in the current housing market. One interesting trend uncovered by the study indicates that 70 percent of buyers are more inclined to purchase a green home over a conventional home. In addition, the survey estimates that within the last three years, more than 330,000 market-rate homes with green features have been built in the United States, representing a $36 billion industry annually. Equally notable, more than half of buyers who purchased green homes earned less than $75,000 a year, indicating that green housing is affordable and accessible to people across all demographics.

According to an article developed by Bion Howard for the USGBC, residential construction processes are still fairly inefficient compared to other industries, as reported to Congress by the U.S. Office of Technology Assessment. In green homes, he said, much inefficiency is addressed and overcome, making the home part of the solution. And an environmentally conscious home does not necessarily cost more, but it will directly benefit the home-owner through improved energy efficiency, reduced use of natural resources, higher levels of comfort and better resale values.

Green home technologies

According to MarketWatch Inc., part of the Wall Street Journal Digital Network, energy-saving technologies today go beyond the simple programmable thermostat and include renewable energy sources, energy-efficient lighting types and controls, and energy monitoring. To be fully optimized, these technologies require a whole-building approach that enables the development of a package of energy-efficiency improvements that achieve performance goals in the home.

Solar or geothermal energy are currently the most common renewable sources incorporated into homes, said Ed Pollock, residential energy research team leader in the U.S. Department of Energy’s (DOE) Office of Energy Efficiency and Renewable Energy (EERE). However, tying a solar energy system into a home requires additional distribution subpanels and circuit breakers, though if the investment is made, a homeowner can use solar power to effectively zero-out his or her monthly electric bill.

“Incorporating wind is even harder for individual homes to use, unless the house is part of a larger development that is in a part of the country in which wind power is feasible,” said John White, energy management and environmental solutions manager for Eaton Electrical Group, Cleveland.

Lighting offers green home construction its greatest energy-efficiency opportunities in the areas of Energy Star-labeled lighting systems and compact fluorescent lamps (CFLs). CFLs also can be used outdoors for security and landscape lighting.

“CFLs are long-lived and appropriate for extreme temperature applications,” White said.

Solid-state technology, such as light-emitting diodes (LEDs) is expected to enter the mainstream market in the next two to three years, Pollock said. Although not yet Energy Star-compliant, draft standards for LEDs are about to be finalized.

Finally, mandates, such as California’s Title 24, are requiring improved energy efficiency through the use of certain types of lighting and use of dimmers and motion sensors in areas such as bathrooms.

Of course, without the use of controls, energy-efficient lighting is only half of the green technology equation.

“Lighting controls that make a home green include special features, such as motion sensors or some sort of timer. DOE’s Building America research program is examining whole-house controls that would be more sophisticated and [would] control all of the systems within a home to provide more flexible, efficient use of lighting,” Pollock said.

Energy-monitoring systems also contribute to a home being considered green and an Innovative Design credit has been approved by the Leadership in Energy and Environmental Design (LEED) for Homes rating system for installed energy management systems that provide real-time feedback to -homeowners, according to Jay Hall, Ph.D., president of Jay Hall & Associates Inc., Annapolis, Md., and LEED for Homes program technical support consultant. There are currently, however, few products on the market that provide that sort of real-time information, although the Energy Monitoring Dashboard from GE provides current and historical feedback on a home’s indoor energy and water consumption as well as levels of emissions, while Eaton’s Home Heartbeat uses wireless sensors to monitor the status of the home’s electronic devices.

“Homeowners that are aware of their usage have a tendency to self-alter their behavior to save energy,” said Mark Johnson, residential group manager for Baker Electric Inc., Escondido, Calif.

Green, energy-efficient homes are also integrated homes. For example, integrated systems allow waste heat from the home’s HVAC system or its appliances to be used to heat water.

“Integration allows homeowners to reduce energy consumption through the use of waste energy and more sophisticated control of energy consumption,” Pollock said.

Other interesting systems for the green home, Hall said, include demand-controlled hot water distribution systems, evapotranspiration demand controllers for irrigation systems that estimate water demand, power venting for hot water heaters, humidistats for air conditioners and bathroom exhausts, exhaust fans in garages, and heat-recovery and energy-recovery ventilators.

Green programs

There are dozens of national, regional and local green building programs, according to Jon Passe, communications coordinator for the Environmental Protection Agency’s Energy Star residential program. These programs define, although somewhat differently, what a green home is; they all start with energy efficiency as a base.

“Some add indoor air and water quality, waste reduction and recycling, sustainability or smart growth requirements and most have a point structure for the home to acquire certification,” Passe said.

The Energy Star program does have some requirements for lighting, but its goal is to set benchmarks for total home energy efficiency, not to mandate what systems are installed.

“Energy Star qualification offers the consumer all of the home features they want plus energy-efficiency improvements that reduce costs and help improve the environment,” Passe said.

In 2007, about 12 percent of national home starts were Energy Star-qualified. These homes are at least 15 percent more energy efficient than homes built to the 2004 International Energy Code.

“With more than 70 percent of American consumers recognizing the Energy Star label, participating in the Energy Star program provides market differentiation for the contractor and increased revenue and customer satisfaction,” Passe said.

First published in 2005, the National Association of Home Builders Model Green Home Building Guidelines provide guidance for builders in green building products and practices for residential design, development and construction. The guidelines cover lot design, resource, energy, water efficiency, indoor environmental quality, homeowner education and global impact. A minimum number of points is required, ensuring all aspects of green building are addressed and a whole-house system approach was used in the project.

“A whole building approach to green home design and construction promotes clear and shared performance goals among the project team members, improved project planning, team selection, and communication and forces the development of a design based on a fundamental, scientific understanding of heat, energy, moisture and pollutant flows,” Hall said.

USGBC’s LEED for Homes program provides a minimum threshold for energy performance that is 15 to 20 percent higher than code requirements.

“LEED for Homes helps promote energy efficiency and provides homeowners with the assurance, through third-party testing, that higher levels of performance will be achieved,” Hall said.

LEED for Homes enables builders and contractors to differentiate their homes using a recognized national brand and provides national consistency in defining the features of a green home. This enables builders anywhere to obtain a green rating. The rating system measures the overall performance of a home in the areas of innovation and design, home location and how they link to the larger community, sustainable sites, water and energy efficiency, materials and resources, indoor environmental quality, and homeowner education.

Innovation opportunities

An educated electrical contractor could be a powerful resource to help the developer build energy-efficient homes, Passe said.

“The contractor can use its technological expertise and knowledge of building practices that increase energy efficiency and help the builder successfully navigate through the various green building programs,” he said.

During the actual installation, contractors can use green best practices to ensure the project meets the performance guidelines of any particular green building program.

An important trend and opportunity for contractors on the horizon involves the 2030 Challenge developed by the American Institute of Architects, which calls for all homes to be net-zero-energy performers by 2030, emitting either no carbon into the atmosphere or offsetting carbon emissions through the use of renewable-energy sources.

“Innovative contractors can offer system components that guarantee or lead to net-zero-energy performance and provide renewable energy systems for pools and hot tubs,” Hall said.

Opportunities also exist for contractors knowledgeable about photovoltaic systems for homes, particularly in those markets that have state incentives, such as California, North Carolina, New Jersey and New York. Plus, the Emergency Economic Stabilization Act of 2008 has extended tax credits of up to 30 percent for consumers who install solar electric systems and provides credits up to $4,000 for installed small wind systems and up to $2,000 for geothermal heat pumps.

“Solar electric installations, upgrading homes with CFLs and LEDs, and promoting smart, computer-controlled integrated homes are all excellent opportunities for contractors to provide innovative, energy-efficient solutions,” Johnson said.

However, providing more sophisticated systems and controls requires the contractor to be more educated about the technology and the requirements of green design.

“Contractors need to understand the whole-building approach to design and work closely with the architects and builders to ensure that they are complying with the construction practices of an airtight house,” Pollock said.

BREMER, a freelance writer based in Solomons, Md., contributes frequently to ELECTRICAL CONTRACTOR. She can be reached at 410.394.6966 or darbremer@comcast.net.