May 1, 2017

Zero is the Hero: Energy Efficient Homes Construct Better Lives

Nearly forty case studies show that DOE Zero Energy Ready Homes can produce as much or more energy as they consume, and save money in the long run

The DOE Zero Energy Ready Home Program includes a list of stringent but common sense requirements.

Would you want a home that is more comfortable, efficient, and durable? Who wouldn’t?

When it comes to efficiency, many builders are beginning to construct and certify new homes that meet the U.S. Department of Energy (DOE) Zero Energy Ready Home Program(Offsite link) requirements. These high-performance homes are so energy efficient that a reasonably sized renewable energy system, like a few rooftop solar panels, can offset all or most of the home’s annual energy consumption. In addition to energy savings, these homes also provide outstanding levels of water savings, comfort, health, and durability.

PNNL building energy-efficiency scientist Theresa Gilbridedelivered 39 case studies to DOE in January that provide evidence of the program’s benefits. The goal of the program is to make zero energy homes available to home buyers in all parts of the country.

Zero for the Win!

Since 2013, the homes have become progressively more energy efficient. Homes are measured using a home energy rating system, or HERS, index, with 100 being equivalent to a home built to the 2006 International Energy Conservation Code—about what most homes are built to today—and 130 being the approximate score for an older home. As of January 2017, many homes in the program are achieving scores of 40 or lower without any solar power, or photovoltaics (PV). When PV roof panels are added, many homes score at or below the coveted HERS score of 0. This means the home is producing at least as much power as it consumes over the course of the year.

The DOE Zero Energy Ready Home Program includes a list of stringent but common-sense requirements. Even with all of the requirements, a zero energy ready home does not have to cost more than standard code built homes. In fact, sometimes these home can be cheaper than standard homes since the slightly higher mortgage payments from the upgrades can be more than offset by the energy bill savings.

This cheerful two-story home in suburban Fort Collins, Colorado really gives its home owners something to smile about—zero energ

A Case Study Example

Philgreen Construction is the lead building contractor on a building project at the REVIVE Fort Collins, Colorado development. The builder and his team are building homes so energy efficient that they have negative utility bills. One such home is the North Star model home, a two-story 1,770 square foot home with 3 bedrooms and 2.5 baths.

To meet the requirements of the DOE Zero Energy Ready Home program and ensure a low HERS score, Philgreen Construction used a high-performance spray foam insulation system to enhance comfort and quiet, comprehensive draft protection, a heat recovery ventilation fresh air system for cleaner, healthier indoor air, an ultra—efficient ground-source heat pump, and high-efficiency appliances and advanced LED lighting technology for energy and water savings. In the North Star model home, this led to a HERS score of -9 <—significantly less than a HERS score of 100 for a typical new code home, or 130 for an average existing home—>and energy bill savings of $3,060 per year.

For more information about the DOE Zero Energy Ready Home Program, go to the EERE website on Zero Energy Ready Homes(Offsite link). Here you can find the requirements, case studies, builder profiles, and much more.

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About PNNL

Pacific Northwest National Laboratory draws on its distinguishing strengths in chemistry, Earth sciences, biology and data science to advance scientific knowledge and address challenges in sustainable energy and national security. Founded in 1965, PNNL is operated by Battelle for the Department of Energy’s Office of Science, which is the single largest supporter of basic research in the physical sciences in the United States. DOE’s Office of Science is working to address some of the most pressing challenges of our time. For more information, visit For more information on PNNL, visit PNNL's News Center. Follow us on Twitter, Facebook, LinkedIn and Instagram.

Published: May 1, 2017

PNNL Research Team

Michael Baechler, Theresa Gilbride, Katie Cort, Margaret Axelson, Rose Bartlett, and Jessica Wisse